Sandro CARBONARI

Pubblicazioni

Sandro CARBONARI

 

137 pubblicazioni classificate nel seguente modo:

Nr. doc. Classificazioni
94 4 Contributo in Atti di Convegno (Proceeding)
37 1 Contributo su Rivista
5 2 Contributo in Volume
1 8 Tesi di dottorato
Anno
Risorse
2021
Finite elements for higher order steel–concrete composite beams
APPLIED SCIENCES
Autore/i: Gara, F.; Carbonari, S.; Leoni, G.; Dezi, L.
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents finite elements for a higher order steel–concrete composite beam model developed for the analysis of bridge decks. The model accounts for the slab–girder partial interaction, the overall shear deformability, and the shear‐lag phenomenon in steel and concrete components. The theoretical derivation of the solving balance conditions, in both weak and strong form, is firstly addressed. Then, three different finite elements are proposed, which are characterised by (i) linear interpolating functions, (ii) Hermitian polynomial interpolating functions, and (iii) interpolating functions, respectively, derived from the analytical solution expressed by means of exponential matrices. The performance of the finite elements is analysed in terms of the solution con-vergence rate for realistic steel–concrete composite beams with different restraints and loading con-ditions. Finally, the efficiency of the beam model is shown by comparing the results obtained with the proposed finite elements and those achieved with a refined 3D shell finite element model.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/286916 Collegamento a IRIS

2021
Post-Earthquake Damage and Vulnerability Assessment of Churches in the Marche Region Struck by the 2016 Central Italy Seismic Sequence
INTERNATIONAL JOURNAL OF ARCHITECTURAL HERITAGE
Autore/i: Canuti, C.; Carbonari, S.; Dall'Asta, A.; Dezi, L.; Gara, F.; Leoni, G.; Morici, M.; Petrucci, E.; Prota, A.; Zona, A.
Classificazione: 1 Contributo su Rivista
Abstract: This paper analyses the observational damage from post-earthquake investigations carried out on churches of the Marche Region struck by the 2016 Central Italy seismic sequence. Such seismic activity seriously damaged many historical buildings and particularly churches, due to their intrinsic inability to develop an efficient box-like resisting mechanism. After the mainshocks, teams of structural engineers were involved in the assessment of damage of churches and in the evaluation of their usability. Collected data are processed in this work to give insight into the occurred damage and to evaluate the vulnerability of the religious buildings of the Region. To this purpose, an architectural background is firstly provided to allow for a classification of the sample, then, the most recurring damage mechanisms are identified, and a global damage index of each church is computed. The distribution of the damage over the Region is commented, as a function of the macro-seismic intensity and other important factors affecting the seismic response. Finally, the overall damage of the sample is compared to that estimated through empirical models available in the literature and comparisons with the results of previous studies are provided.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269907 Collegamento a IRIS

2021
Monitoring the Modal Properties of an RC School Building during the 2016 Central Italy Seismic Swarm
JOURNAL OF STRUCTURAL ENGINEERING
Autore/i: Gara, F.; Arezzo, D.; Nicoletti, V.; Carbonari, S.
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents results from the dynamic monitoring of a reinforced concrete school building located in Camerino (central Italy) during the seismic swarm following the first main shock of the Central Italy earthquake that occurred in August 2016. After the main shock of August 24th, ambient vibration tests were executed on the building to identify its modal dynamic behavior, which was assumed as benchmark to study changes in the structural response because of the subsequent events. A three-day dynamic monitoring was then performed with the aim of investigating changes in the dynamic behavior of the building subjected to ambient and seismic excitations. A procedure to identify the nonlinear response of the structure subjected to seismic events is presented, starting from an optimization methodology that permits the identification of the structure dynamics within time windows in which the building dynamic behavior can be considered linear time-invariant. Data show the variability of the modal properties, resonance frequencies, and damping ratios of the building, with the earthquake intensity.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/289951 Collegamento a IRIS

2021
Dynamic monitoring of buildings as a diagnostic tool during construction phases
JOURNAL OF BUILDING ENGINEERING
Autore/i: Nicoletti, V.; Arezzo, D.; Carbonari, S.; Gara, F.
Classificazione: 1 Contributo su Rivista
Abstract: The paper discusses the usefulness of the dynamic characterization of buildings based on the use of ambient vibration tests at different construction phases. The proposed experimental procedure, integrated with more conventional non-destructive in-situ tests for the estimation of the material mechanical properties, foresees the monitoring of the evolution of the building modal properties during the main construction phases. The monitoring makes it possible to assess the correctness of the construction through comparison with expected trends, and to consider possible countermeasures in case of unexpected behaviours. A case study, monitored during its construction, is presented to show the additional value of information obtained from the proposed experimental approach: (i) tests on the bare frame can be adopted to validate the design numerical model of the structure, in which non-structural elements are neglected in performing ultimate limit state verifications, (ii) the proposed monitoring allows the identification of the infills contribution on the building dynamics, providing useful information to address the interaction problem between structural and non-structural elements that may be detrimental at ultimates, and (iii) trends of resonance frequencies during the construction, validated through numerical applications, constitute an important tool for interpreting data from structural health monitoring system, as well as to establish alert thresholds of demand parameters (e.g. relevant to the building occupancy or structural damage).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/293681 Collegamento a IRIS

2021
Dynamic behavior of soil-foundation-structure systems subjected to scour
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Antonopoulos, C.; Tubaldi, E.; Carbonari, S.; Gara, F.; Dezi, F.
Classificazione: 1 Contributo su Rivista
Abstract: Earthquake and scouring are the leading causes of bridge failure worldwide, resulting not only in casualties and fatalities but also in enormous societal and economic losses. A great number of bridges in earthquake-prone countries cross rivers and have shallow foundations, which renders them highly vulnerable to the combined effects of earthquake and flood-induced scour. Thus, the research on the dynamic response of bridges with shallow foundations under scour and earthquake hazards is timely and imperative. This study investigates the problem through the development of a numerical model for evaluating the effect of scour on the impedance functions of a massless rigid strip foundation resting on a homogenous elastic half-space. The developed impedance functions are then used in an extensive parametric study analyzing the changes of the fundamental frequency of bridge piers for different combinations of the geometrical and mechanical properties of the soil-structure-foundation system. The study results shed light on the effects of scour on the dynamic properties and fundamental frequency of vibration of bridges with shallow foundations and have important implications on the development of inverse techniques for scour identification based on the evaluation of the changes in the bridge modal properties.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/293282 Collegamento a IRIS

2020
Numerical and simplified methods for soil-pile interaction analysis
GEOTECHNICAL ENGINEERING
Autore/i: Dezi, F.; Carbonari, S.; Morici, M.; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents a review of the analytical and numerical procedures developed by the authors for the dynamic analysis of soil-pile foundation systems subjected to the propagation of seismic waves in the soil. Inclined and vertical single piles and groups constituted by piles with a generic inclination are addressed. For the former, an analytical approach based on the beam on dynamic Winkler foundation approach is adopted; the pile is modelled as a Euler-Bernoulli beam and the soil-pile interaction is captured by defining soil impedances relevant to the harmonic vibrations of rigid disks available in the literature. The coupled flexural and axial behaviour of the pile is solved analytically exploiting exponential matrices. The pile group dynamic problem is similarly formulated but the solution is achieved exploiting the finite element approach. Besides numerical models, simplified approaches based on static equivalent methods and simplified formulas are also addressed to estimate the maximum kinematic stress resultants on vertical piles subjected to lateral seismic excitations. The reliability of the presented tools in capturing the dynamic stiffness and the overall kinematic response of pile foundations is shown by comparing results with those available in the literature or achieved through refined finite element models. From an engineering point of view, the proposed approaches assure a sufficient accuracy and may substitute refined computational demanding numerical models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/283312 Collegamento a IRIS

2020
Expeditious methodology for the estimation of infill masonry wall stiffness through in-situ dynamic tests
CONSTRUCTION AND BUILDING MATERIALS
Autore/i: Nicoletti, V.; Arezzo, D.; Carbonari, S.; Gara, F.
Classificazione: 1 Contributo su Rivista
Abstract: In this paper a procedure to experimentally estimate the stiffness of masonry internal partitions and infill walls is proposed with the aim of providing a practical tool to reduce uncertainties in the finite element modelling of frame buildings when partitions and infills must be included. The proposed methodology, based on in-situ impact load tests and numerical modelling, is presented. The methodology is validated through an experimental campaign on a laboratory mock-up and applied to a real reinforced concrete frame building. The proposed methodology revealed capable to provide a very accurate estimate of the infill stiffness to be adopted in the building modelling.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/283984 Collegamento a IRIS

2020
Measurements of ambient vibrations for a cable-stayed bridge including the soil-foundation system
Proceedings of the International Conference on Structural Dynamic , EURODYN
Autore/i: Nicoletti, V.; Arezzo, D.; Carbonari, S.; Dezi, F.; Gara, F.
Editore: European Association for Structural Dynamics
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper deals with the dynamic characterization of a cable-stayed steel-concrete composite bridge located on the Saline river, close to Pescara in central Italy, carried out during the static proof load test. The bridge is 189 m long and is composed by 4 inclined steel pipe pylons that sustain a steel-concrete composite deck by means of 40 stay cables. During the proof test, an extensive experimental campaign is carried out to check the overall structural performance before the bridge openings to traffic. In detail, the main girder deflections, the axial loads on strands, the pylons displacements, and the bearings displacements were monitored through conventional and non-conventional techniques, such as the laser scanner technique. In addition, an accelerometer array is installed during the proof test to evaluate the dynamic characteristics of the structure in its loaded and unloaded conditions through ambient vibration measurements. Sensors are positioned on the deck, on two pylons and on the foundation system, in order to characterize the whole structural dynamic behavior, including the contribution of the soil-foundation compliance. With reference to the unloaded bridge, the latter issue is analyzed in this paper, focusing on the different restraint condition exerted by the soil-foundation system of the pylons, because of the different embedment of the reinforced concrete basements. It is shown that the soil-foundation compliance has greater effects on higher modes for the bridge at hand and that possible non-symmetries due to the different foundation degree of restraint can be suitably captured through ambient vibration tests. Data from experimental tests are crucial not only to check consistency between the design and the real structure before the opening to traffic, but also to calibrate refined finite element models to be used for the structural health monitoring of the bridge. In this sense, a reliable evaluation of the contribution of the soil-foundation system is mandatory, considering that the bridge, having foundations located in the riverbed, is prone to the scour hazard.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/287438 Collegamento a IRIS

2020
Static and dynamic testing of the “Filomena Delli Castelli” bridge
Belgian, Dutch and French National Groups of IABSE – Young Engineers Colloquium
Autore/i: Innocenzi, Raoul Davide; Carbonari, Sandro; Gara, Fabrizio; Dezi, Luigino
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper describes the static and dynamic testing of the “Filomena Delli Castelli”cable-stayed bridge over the Saline River, in the Pescara province (Italy), having main span of 103.4 m and total length of 188.6 m.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/291654 Collegamento a IRIS

2020
Dynamic monitoring of bridges during static load tests: influence of the dynamics of trucks on the modal parameters of the bridge
JOURNAL OF CIVIL STRUCTURAL HEALTH MONITORING
Autore/i: Gara, F.; Nicoletti, V.; Carbonari, S.; Ragni, L.; Dall'Asta, A.
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents results of an extensive experimental campaign carried out during the construction phases of a base-isolated bridge across the Potenza river in central Italy. The structure is constituted by a half-through steel arch bridge composed by two coupled weathering steel tubular arches sustained by thirty couples of hangers and by two approaching viaducts. The bridge has a continuous twin-girder steel–concrete composite deck. During construction, impact load tests were carried out on hangers as well as on other tie elements to estimate their tension force from the relevant resonance frequencies. During the proof test, relative displacements occurred between the upper and lower plates of the seismic isolators are measured for different loading conditions. In addition, ambient vibration tests are performed during the final static load tests to investigate the bridge dynamics subjected to different loading conditions. Comparisons of test results with the numerical predicted values contributed to evaluate the consistency between the design and the real structure at different construction stages. Dynamic identification tests contributed to identify the significance of the truck–bridge interaction in the interpretation of the bridge dynamics evaluated experimentally.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/273422 Collegamento a IRIS

2020
Seismic Retrofit Assessment of a School Building through Operational Modal Analysis and f.e. Modeling
JOURNAL OF STRUCTURAL ENGINEERING
Autore/i: Gara, F.; Carbonari, S.; Roia, D.; Balducci, A.; Dezi, L.
Classificazione: 1 Contributo su Rivista
Abstract: The paper deals with the dynamic characterization of a reinforced concrete (RC) frame school building in central Italy before and after the seismic retrofitting, obtained by coupling the building with an innovative patented seismic dissipative protection system. Before the retrofit, ambient vibration tests were performed to evaluate frequencies and mode shapes for developing finite-element (f.e.) models describing the school dynamic behavior in operational conditions. Several finite-element models with increasing level of detail are presented, from the bare frame model, based on the assumptions and simplifications usually adopted for design purposes, to an upgraded model taking account of secondary and nonstructural elements (e.g., internal and external walls, screeds, roofing, floor tiles, and plasters) as well as the interaction between structure and retaining walls. The latter was used to develop the design model of the seismic retrofitting system, which aims to assure the immediate occupancy of the building in the case of severe earthquakes limiting damage to nonstructural components. Tests were repeated after the retrofit to check consistency with numerical design predictions. Comparisons between experimental and numerical modal parameters are shown discussing the usefulness of ambient vibration tests.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/285066 Collegamento a IRIS

2020
Benefits of inclined pile foundations in earthquake resistant design of bridges
ENGINEERING STRUCTURES
Autore/i: Gonzalez, F.; Carbonari, S.; Padron, L. A.; Morici, M.; Aznarez, J. J.; Dezi, F.; Maeso, O.; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: This paper studies the effects of the use of inclined pile foundations on the seismic response of bridges, and shows that this type of foundation is able to promote significant reductions in the ductility demand of reinforced concrete piers. To this end, a set of nine multi-span roadway viaducts with different pier heights and span lengths is defined. Each configuration is designed and dimensioned in detail following a displacement-based approach, considering both linear and non-linear expected behaviours and assuming different target ductilities for piers. The systems are assumed to be founded on a specific soil profile, and suitable pile foundation layouts and dimensions are determined for each case, with four different pile rake angles (including the vertical case) in each configuration. Soil-structure interaction phenomena are incorporated through the corresponding frequency-dependent impedance functions and kinematic interaction factors. The transverse response of the viaducts, subject to a set of seven suitable scaled real accelerograms, is computed and analysed making use of a substructuring approach and non-linear time-domain analysis in which a lumped parameter model is adopted to represent the foundation response. Results, presented not only in terms of ductility demand but also of energy dissipated in the structural system by damping or by yielding, suggest that inclined piles are clearly beneficial to the seismic response of bridges, contributing to significant reductions in ductility demand due to the particular kinematic seismic response of this type of foundations and associated reductions in the input seismic energy to the system.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/271995 Collegamento a IRIS

2019
Identification of infill masonry walls stiffening contribution on the dynamic behaviour of steel frames
8th IOMAC - International Operational Modal Analysis Conference, Proceedings
Autore/i: Nicoletti, Vanni; Regni, Marco; Speranza, Elisa; Arezzo, Davide; Carbonari, Sandro; Gara, Fabrizio
Editore: International Operational Modal Analysis Conference (IOMAC)
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper deals with the influence of infill masonry walls on the dynamic behaviour of steel structures. The research is based on the experimental and numerical results obtained for a real scale laboratory mock-up, consisting of a one-storey two-bays steel-concrete composite frame. Ambient vibration tests followed by impact load tests were performed after the construction of the IMWs to estimate the dynamic properties of the entire structure and to investigate changes of modal parameters (natural frequencies and mode shapes) due to the contribution of the non-structural components. Furthermore, impact load tests were performed on some IMWs to identify their out-of-plane modal parameters; finally, a methodology to estimate parameters for a 2D modelling of the IMWs is proposed and validated. The numerical results show a very good agreement with the experimental ones, proving the reliability of the estimated IMWs stiffnesses through the proposed procedure.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267569 Collegamento a IRIS

2019
Experimental assessment of the expected impact of a bridge seismic retrofit through ambient vibration tests
8th IOMAC - International Operational Modal Analysis Conference, Proceedings
Autore/i: Minnucci, Lucia; Regni, Marco; Speranza, Elisa; Carbonari, Sandro; Gara, Fabrizio
Editore: International Operational Modal Analysis Conference (IOMAC)
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents and discusses results of ambient vibration tests performed on the Moscosi Bridge in Cingoli (Italy) before and after the execution of seismic retrofitting works. The aim of the first tests is to evaluate the dynamic parameters of the bridge, such as the eigenfrequencies, the mode shapes and the relevant modal damping ratios, in order to build up a numerical model and, through it, to predict the behaviour of the bridge after the interventions. The dynamic characterization of the bridge is obtained through the measurements of ambient vibrations, which are processed with the Covariance-driven Stochastic Subspace Identification. The information derived by the calibrated model are compared with the results of a second ambient vibrational measurement campaign, and the effectiveness of the retrofit is assessed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267570 Collegamento a IRIS

2019
A practical procedure for time-domain soil-structure interaction analysis of structures on pile foundations
Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions
Autore/i: CARBONARI, Sandro; MINNUCCI, LUCIA; Dezi, Francesca; Morici, Michele; Leoni, Graziano
Editore: CRC Press Taylor & Francis Group
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a simplified procedure for the time domain soil-structure interaction analysis of piled structures, based on the use of a lumped parameter model for the approx-imation of the frequency-dependent dynamic stiffness of foundations. The lumped model can be implemented in commercial software to perform linear or nonlinear dynamic anal-yses of structures founded on piles taking into account the frequency dependent coupled roto-translational, vertical and torsional behaviour of the soil-foundation system. Closed-form formulas, calibrated with a nonlinear least square procedure based on data provided by an extensive non-dimensional parametric analysis, are used for estimating parameters of the lumped system. Formulas, which allow defining lumped models representative of pile groups with square layout and different number of piles embedded in soft and stiff soils, can be straightforwardly implemented to perform inertial structural analyses ac-counting for the dynamic behaviour of the soil-foundation system. Some applications on typical bridge piers are presented to show a practical use of the proposed procedure. Re-sults demonstrate the capability of the approach in capturing the actual dynamic response evaluated through a rigorous soil-structure interaction analysis.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267571 Collegamento a IRIS

2019
An integrated permanent dynamic monitoring system of a tall building in central Italy
8th IOMAC - International Operational Modal Analysis Conference, Proceedings
Autore/i: Arezzo, Davide; Regni, Marco; Carbonari, Sandro; Gara, Fabrizio
Editore: International Operational Modal Analysis Conference (IOMAC)
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents results of the dynamic monitoring of a 10-storey r.c. tower in central Italy, focusing on the effects of ambient conditions. The installed monitoring system consists of a set of three accelerometers located on the last floor of the tower, including a velocimeter located at the foundation level and an acquisition software that, through a specifically developed algorithm based on operational modal analysis techniques, automatically extracts the modal parameters of the building from the accelerometric recordings. Ambient registrations derive from a weather station installed on the roof of the tower. Effects of the ambient parameters on the dynamic properties of the building are presented and discussed. Moreover, the building response to low intensity seismic events registered during the monitoring period is compared with that obtained from a calibrated numerical model by applying at the base the input registered by the velocimeter.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267568 Collegamento a IRIS

2019
Evaluation of dynamic soil-pile interaction based on both full scale in situ tests and numerical simulations
Earthquake Geotechnical Engineering for Protection and Development of Environment and Constructions
Autore/i: Dezi, Francesca; ROIA, DAVIDE; Chiara Capatti, Maria; CARBONARI, Sandro; GARA, Fabrizio; Leoni, Graziano; Morici, Michele
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents some comparisons between results obtained by full-scale experimental dynamic tests and numerical simulations for the evaluation of the dynamic behaviour of soil-pile foundation systems. Two experimental campaigns were considered for this scope: one conducted on vibro-driven steel pipe piles in nearshore environment and the other on vertical injected and not injected micropiles in an alluvial silty deposit. Experimental cam-paigns include ambient vibration and impact tests, as well as snap back and forced vibra-tion tests. A numerical procedure, developed to study the kinematic and inertial interaction of pile foundations in horizontally layered soil profiles, was applied to predict the re-sponse of the 3 types of piles realized in different soil deposits. The primary objective of the comparisons was to assess the accuracy of the numerical procedure in predicting the dynamic response of the pile-foundation system varying the pile construction method and soil nature surrounding the pile shaft.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267572 Collegamento a IRIS

2019
Field tests on a soil-foundation-structure system subjected to scour
Atti del XVIII Convegno ANIDIS L'ingegneria sismica in Italia
Autore/i: Tubaldi, Enrico; Lupo, Rosa; Mitoulis, Stergios; Argyroudis, Sotiris; Gara, Fabrizio; Ragni, Laura; Carbonari, Sandro; Dezi, Francesca
Editore: Pisa University Press srl
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Earthquakes and foundation scour are the major causes of bridge failure worldwide. Many bridges in earthquake-prone countries have shallow foundations, whose stability and seismic vulnerability can be significantly undermined by flood-induced scour. This article provides the first results of the “DYMOBRIS” project (DYnamic identification and MOnitoring of scoured BRIdgeS under earthquake hazard), a H2020-SERA EU-funded project aiming at i) developing a methodology for non-invasive detection of scour in bridges with shallow foundations based on vibration monitoring, and ii) quantifying the effects of scour on the seismic vulnerability of these Soil-Foundation-Structure (SFS) systems. The experimental campaign involves various tests, from ambient vibration to force vibration, on the EuroProteas prototype under different scour conditions. The preliminary finite element models developed for defining the scour profile to be imposed in the in-field tests are presented here, together with some results concerning the effects of scour on the SFS dynamic properties.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269908 Collegamento a IRIS

2019
Risultati del monitoraggio dinamico di un edificio scolastico a Camerino a valle del sisma del centro Italia dell’agosto 2016
Atti del XVIII Convegno ANIDIS L'ingegneria sismica in Italia
Autore/i: Arezzo, Davide; Speranza, Elisa; Carbonari, Sandro; Gara, Fabrizio
Editore: Pisa University Press srl
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Il lavoro presenta i risultati del monitoraggio dinamico di un edificio scolastico situato a Camerino (MC), durante la sequenza sismica che ha colpito l’Italia centrale nel 2016. L’edificio ospita il liceo Classico e Scientifico “Varano” ed è situato nel centro storico di Camerino; si tratta di un fabbricato con struttura a telaio in cemento armato e tamponature in laterizio realizzato negli anni ’60 e adeguato sismicamente nel 2013 con il sistema delle Torri Dissipative. Nel 2016, a valle del sisma del 24 agosto, è stato installato sull’edificio un sistema di monitoraggio dinamico costituito da accelerometri posizionati agli ultimi due piani della struttura e a livello delle fondazioni. Le registrazioni del moto alla base e della risposta dell’edificio ai piani superiori per effetto dei numerosi eventi sismici successivi al sisma principale e delle vibrazioni ambientali nei periodi di intervallo tra i sismi, hanno consentito di identificare i parametri modali grazie a tecniche input-output (N4SID), in occorrenza degli eventi sismici, e alle consolidate tecniche output-only (SSI), nei periodi di quiete. Ciò ha consentito di cogliere l’evoluzione delle caratteristiche dinamiche dell’edificio durante lo sciame sismico.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269911 Collegamento a IRIS

2019
Preliminary probabilistic assessment of the seismic response of link slab viaducts
Atti del XVIII Convegno ANIDIS L'ingegneria sismica in Italia
Autore/i: Minnucci, Lucia; Scozzese, Fabrizio; Carbonari, Sandro; Dall’Asta, Andrea; Gara, Fabrizio
Editore: Pisa University Press srl
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Recent seismic events occurred in Central Italy drew the attention towards the resilience of the Italian road network, which is characterised by a significant number of old reinforced concrete bridges and viaducts. In this context, the fragility assessment of existing bridges is crucial, since their collapse or loss in functionality after earthquakes may lead to significant economic and social consequences. As a preliminary study oriented to characterizing the fragility level of the Italian bridge heritage, this work focuses on the real case study of the Chiaravalle viaduct, located in Central Italy, which may be representative of a widespread class of reinforced concrete bridges in Italy. The viaduct is a continuous multi-span bridge consisting of precast simply supported V-shaped beams connected by a continuous upper slab. A numerical model is developed in order to capture the failure mechanisms most likely to occur for this bridge typology subjected to seismic actions. A probabilistic assessment of the seismic response of the bridge is carried out by performing multiple stripe analysis (MSA), and a preliminary interpretation of the results is provided. Future studies will be aimed to the development of fragility curves, by accounting for all the relevant demand parameters and limit states.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269910 Collegamento a IRIS

2019
Una formulazione approssimata delle impedenze e del moto di fondazione per l’analisi inerziale di strutture fondate su pali
Atti del XVIII Convegno ANIDIS L'ingegneria sismica in Italia
Autore/i: Morici, Michele; Minnucci, Lucia; Carbonari, Sandro; Dezi, Francesca; Leoni, Graziano
Editore: Pisa University Press srl
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Questo lavoro presenta una procedura semplificata per l’analisi di interazione terreno-struttura nel dominio del tempo di strutture fondate su pali. La procedura si basa sull’utilizzo di un modello a parametri concentrati per l’approssimazione della rigidezza dinamica del sistema fondazione-terreno che risulta dipendente dalla frequenza; l’approccio può essere facilmente implementato in software commerciali per l’analisi lineare e non lineare di strutture e permette di tener conto del comportamento traslazionale, rotazionale e roto-traslazionale di fondazioni profonde in funzione della frequenza di eccitazione e delle caratteristiche del deposito. Per la stima dei parametri del modello sono state utilizzate espressioni analitiche calibrate con regressioni non lineari ai minimi quadrati sulla base di dati ottenuti da una esaustiva analisi parametrica non dimensionale. Le formule, che permettono di definire modelli a parametri concentrati rappresentativi di fondazioni quadrate con differente numero di pali in rigidi depositi di varia natura, possono essere direttamente adottate per eseguire analisi inerziali delle sovrastrutture includendo il comportamento dinamico del sistema terreno-fondazione. Alcune applicazioni su pile da ponte singole sono in ultimo presentate con il fine di mostrare l’utilizzo pratico della procedura proposta. I risultati dimostrano le potenzialità dell’approccio nel cogliere la risposta dinamica attesa delle strutture, valutata attraverso una analisi di interazione terreno-struttura più rigorosa.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269913 Collegamento a IRIS

2019
Influenza delle tamponature sul comportamento dinamico di strutture a telaio in acciaio: sperimentazione su un caso studio
Atti del XVIII Convegno ANIDIS L'ingegneria sismica in Italia
Autore/i: Nicoletti, Vanni; Arezzo, Davide; Carbonari, Sandro; Gara, Fabrizio
Editore: Pisa University Press srl
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: L’articolo riguarda un’estesa campagna sperimentale finalizzata all’analisi dell’influenza delle tamponature sul comportamento dinamico di strutture intelaiate in acciaio. La sperimentazione è stata condotta in laboratorio su un telaio in acciaio con soletta composta in c.a. e lamiera grecata, sul quale sono state eseguite prove di impatto, di vibrazione ambientale e di spinta e rilascio, per le quali vengono descritte le procedure seguite, la strumentazione adottata e i principali risultati ottenuti. Le prove sono state eseguite prima e dopo la realizzazione di tamponature leggere in laterizio forato e intonaco al fine di valutare il contributo fornito, in termini di rigidezza, sul comportamento dinamico globale del telaio soggetto ad azioni tali da mantenere la struttura e le pareti in campo elastico. Per concludere, viene presentato un confronto tra i risultati ottenuti con le diverse prove che, nonostante lascino tutte la struttura in campo elastico, sono caratterizzate da un diverso livello di eccitazione e forniscono risultati in alcuni casi piuttosto differenti.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269909 Collegamento a IRIS

2019
The significance of soil-foundation compliance on the dynamic identification of the Chiaravalle viaduct
Atti del XVIII Convegno ANIDIS L'ingegneria sismica in Italia
Autore/i: Carbonari, Sandro; Dezi, Francesca; Gara, Fabrizio; Leoni, Graziano
Editore: Pisa University Press srl
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper addresses the significance of soil-structure interaction on the dynamic behaviour of the “Chiaravalle viaduct”, based on ambient vibration measurements and numerical simulations through a finite element model. The viaduct is located in Central Italy and is founded on piles in an eluvial-colluvial soil deposit. Experimental modal properties are evaluated by means of the operational modal analysis on accelerometric data, and the role of soil-structure interaction in the interpretation of tests is identified by means of a refined finite element model of the viaduct. In the soil-structure interaction models the local site conditions in correspondence of each bridge pier (resulting from geotechnical and geophysical investigations) are taken into account in the definition of the soil-foundations impedances. Comparisons between the experimental and numerical results highlight the role of the pile-soil-pile interaction, the radiation problem, the pile cap embedment and the variability of the soil stratigraphy along the longitudinal direction of the viaduct in the interpretation of the experimental data.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269912 Collegamento a IRIS

2019
Evaluation of fragility curves of a reinforced concrete viaduct in Central Italy: a preliminary analysis
Atti del 1st fib Italia YMG Symposium on Concrete and Concrete Structures
Autore/i: MINNUCCI, LUCIA; SCOZZESE, Fabrizio; CARBONARI, Sandro; Dall’Asta, Andrea; GARA, Fabrizio
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Recent seismic events occurred in Central Italy drew the attention towards the resilience of the Italian road network, which is characterised by a significant number of old reinforced concrete bridges and viaducts. In this context, the fragility assessment of existing bridges is crucial, since their collapse or loss in functionality after earthquakes may lead to significant economic and social consequences. As a preliminary study oriented to characterizing the fragility level of the Italian bridge heritage, this work focuses on the real case study of the Chiaravalle viaduct, located in Centre Italy, which may be representative of a widespread class of reinforced concrete bridges in Italy. The viaduct is entirely characterized by a reinforced concrete structure, with a link continuous slab on simply supported V-shaped girders. After a preliminary study on the current structural health of the bridge, a numerical model is developed in order to capture the failure mechanisms most likely to occur. Fragility curves, built by accounting for all the relevant demand parameters and limit states, provide useful insights about the main structural deficiencies of the system at hand.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/275315 Collegamento a IRIS

2019
First analysis of data concerning damage occurred to churches of the marche region following the 2016 central Italy earthquakes
BOLLETTINO DI GEOFISICA TEORICA E APPLICATA
Autore/i: Carbonari, S.; Dall'asta, A.; Dezi, L.; Gara, F.; Leoni, G.; Morici, M.; Prota, A.; Zona, A.
Classificazione: 1 Contributo su Rivista
Abstract: The seismic sequence that struck central Italy from August to October 2016 caused severe damage to many historical and artistic buildings. In particular, churches were widely affected due to the intrinsic peculiarities of their structural system, unable to develop an efficient box-like resisting mechanism. After the seismic events, teams of experts carried out a massive survey of churches to assess both the occurred damage and their usability. Teams were coordinated by the Department of Civil Protection and the Ministry of Cultural Heritage. In this paper, a methodology for processing the data recorded during the inspections of a number of churches of the Marche region is proposed and used to analyse a sample data set. Starting from the subdivision of the sampled churches into homogeneous typologies, the most recurring damage mechanisms are identified. In addition, the global damage index of each church is correlated with the relevant highest pseudo spectral acceleration at period 0.30 s registered at the site as a consequence of the main shocks; relationships between the seismic intensity and the observed damage are then derived from such a correlation. Finally, the overall damage occurred to churches of the sample is compared to that estimated through empirical models available in the literature.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/269326 Collegamento a IRIS

2019
Local failure mechanisms of existing steel-concrete composite decks
Atti del XXVII CONGRESSO C.T.A.
Autore/i: Minnucci, Lucia; Carbonari, Sandro; Dezi, Luigino; Gara, Fabrizio; Dall'Asta, Andrea
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The design of Steel-Concrete Composite (SCC) bridges is usually oriented to the solution of global problems, governed by strength and ductility issues of the whole structure, while minor attention is generally given to local effects, associated with the transfer mechanisms of inertia forces from decks to substructures. However, local failure mechanisms of the deck may be of importance since they may compromise the overall response of the bridge, especially for existing bridges, designed ac-cording to lower seismic actions compared to those defined by modern codes. In this paper, the seismic response of an existing SCC bridge is investigated, focusing on the role of local failure mechanisms of the deck on the overall response of the bridge. Two local paths for the seismic action are analyzed: the first involves the shear connection through which inertia forces act-ing at the level of the concrete slab are firstly transferred to steel members; the second is represented by truss cross-beams at supports, one of the most widespread typologies for existing SCC decks, through which the shear forces are transferred to bearings and substructures. Results of seismic analyses on the selected case study are shown and discussed, highlighting the vulnerabilities of the investigated local components.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/273425 Collegamento a IRIS

2019
Sustainable Engineering for Resilient Built and Natural Environments
The First Outstanding 50 Years of “Università Politecnica delle Marche”
Autore/i: Alici, Antonello; Bocci, Maurizio; Bonvini, Paolo; Brocchini, Maurizio; Calamai, Alessandro; Canestrari, Francesco; Capozucca, Roberto; Carbonari, Alessandro; Carbonari, Sandro; Cardone, Fabrizio; Clementi, Francesco; Clini, Paolo; Cocchi, Giammichele; Corvaro, Sara; Darvini, Giovanna; Davì, Fabrizio; Dezi, Luigino; Di Giuseppe, Elisa; D’Orazio, Marco; Ferretti, Maddalena; Ferrotti, Gilda; Gara, Fabrizio; Giretti, Alberto; Graziani, Andrea; Lancioni, Giovanni; Lemma, Massimo; Lenci, Stefano; Lorenzoni, Carlo; Malinverni, Eva Savina; Mancinelli, Alessandro; Mariano, Fabio; Mentrasti, Lando; Mondaini, Gianluigi; Montecchiari, Piero; Munafò, Placido; Naticchia, Berardo; Postacchini, Matteo; Quagliarini, Enrico; Quattrini, Ramona; Ragni, Laura; Serpilli, Michele; Soldini, Luciano; Virgili, Amedeo; Zampini, Giovanni
Editore: Springer
Classificazione: 2 Contributo in Volume
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/272866 Collegamento a IRIS

2019
Seismic response of bridge piers on pile groups for different soil damping models and lumped parameter representations of the foundation
EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS
Autore/i: González, Francisco; Padrón, Luis A.; CARBONARI, Sandro; Morici, Michele; Aznárez, Juan J.; Dezi, Francesca; Leoni, Graziano
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents a wide parametric study aimed at elucidating the influence, on the computed seismic response of bridge piers, of two related aspects of the model: (1) the adoption of the classical hysteretic or the causal Biot's damping models for the soil and (2) the use of two different lumped parameter models of different complexity and accuracy to approximate the impedances of the pile foundation. A total of 2072 cases, including different superstructures, pile foundations, soil deposits, and seismic input signals, are studied. The results are presented so that the influence of the different parameters involved in the analysis can be assessed. From an engineering point of view, both lumped parameter models provide, in general, sufficiently low errors. The choice of the most adequate model for each case will depend not only on the configuration of the structure and the soil‐foundation system but also on the assumed soil damping model, whose influence on the computed seismic responses is relevant in many cases. The nonphysical behaviour provided by the classical hysteretic damping model for the soil at zero frequency generates issues in the process of fitting the impedance functions. It is also found that larger deck displacements are predicted by Biot's model due to the higher damping at low frequencies provided by the classical hysteretic damping model.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/261977 Collegamento a IRIS

2019
Simple formulas for estimating a lumped parameter model to reproduce impedances of end-bearing pile foundations
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Morici, Michele; Minnucci, Lucia; Carbonari, Sandro; Dezi, Francesca; Leoni, Graziano
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents simple formulas to evaluate parameters of a lumped system reproducing the frequency-dependent dynamic stiffness of end-bearing pile foundations. The model can be implemented in commercial finite element software and allows performing inertial soil-structure interaction analyses of structures considering the coupled roto-translational, vertical and torsional behaviour of the soil-foundation system. Pile groups arranged in a square layout are considered; the soil profile is constituted by a homogeneous deformable soil layer overlying a bedrock where piles are socked for a fixed length. Formulas are calibrated with a nonlinear least square procedure, based on data provided by an extensive non-dimensional parametric analysis of the soil-foundation systems, performed with a Winkler's type model, previously developed by the authors, which assumes soil and piles to behave linearly. Firstly, the suitability of the adopted numerical tools in capturing the dynamic stiffness of end-bearing foundations is proven. Then, capabilities of the proposed formulas in estimating parameters of the best lumped systems are shown, and, for some case studies, comparisons of non-null terms of the impedance matrix obtained through the best lumped system, the one computed through the formulas, and the impedances resulting from the dynamic analyses, are presented. Finally, some applications of the proposed formulas in the framework of the seismic soil-structure interaction analysis of bridges are shown to demonstrate the capability of the adopted lumped system and the formula efficiency in assuring a reliable evaluation of the superstructure seismic response, with respect to that obtained from a more rigorous approach.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264706 Collegamento a IRIS

2019
A performance-based approach for the design of coupled dolphin-fender berthing structures
MARINE STRUCTURES
Autore/i: Carbonari, Sandro; Antolloni, Giulia; Gara, Fabrizio; Lorenzoni, Carlo; Mancinelli, Alessandro
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents a performance-based approach for the design of flexible breasting dolphins equipped with marine fenders, often used in jetties belonging to offshore oil terminals. Since the distance of the breasting system to the mooring one and to the oil terminal is generally limited for serviceable and operational issues, the proposed design methodology, based on the kinetic energy approach, assumes a predetermined displacement for the dolphin, as well as a desired performance of the fender, and allows evaluating the stiffness of the flexible system required to achieve the desired energy absorption capacity. The design procedure accounts for the dolphin-fender interaction, as well as for the soil-embedded dolphin interaction, and it is specialised considering the common technical solutions adopted in the design of breasting dolphins. The approach is applied to a hypothetical case study consisting of a new berthing structure for a coastal terminal located on the Middle Adriatic Sea, in Italy, presenting non-ideal conditions for the installation of flexible dolphins. Applications demonstrate the effectiveness of the proposed approach and the role of the dolphin-fender interaction in withstanding the berthing actions, making it possible to design a flexible berthing structure also in the case of relatively shallow water depths.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/261976 Collegamento a IRIS

2019
Effects of uncertainties of soil and pile mechanical properties on the dynamic stiffness of deep foundations in homogenous deposits
Eccomas Proceedia COMPDYN (2019) 4157-4165
Autore/i: Minnucci, Lucia; Dezi, Francesca; Carbonari, Sandro; Morici, Michele; Gara, Fabrizio; Leoni, Graziano
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In the soil-structure interaction framework, among the results of the soil-foundation system analysis (kinematic analysis) the dynamic impedance functions represent the force-displacement relationships of the compliant restraint for the superstructure. The intrinsic varia-bility of soil parameters and of design materials represents an uncertainty source which is nec-essary to include in the definition of the soil-foundation model, in order to predict the super-structure response adequately. The aim of this work is to evaluate effects of uncertainties on soil dynamic and mechanical properties on the impedance matrix of single piles in homogeneous soils, focusing on the sensitivity of the parameters. A Quasi Monte Carlo (QMC) simulation with sampling based on Sobol’ sequence is performed starting from the probabilistic distribu-tion of three main parameters characterizing the soil-piles response, i.e. the soil density, the shear waves velocity and the concrete elastic modulus of piles, available from the literature. The analyses are carried out through the numerical model developed by the Authors and a sen-sitivity study on the optimal number of simulations is performed, comparing the use of Quasi-random sampling with the classical Monte Carlo simulation technique. Moreover, results of sensitivity studies show the influence of variability of each considered mechanical parameter on the global response of the soil-foundation system.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267575 Collegamento a IRIS

2019
An Overview of the Structural Safety-Oriented Research in the Region Marche Seismic Area
The First Outstanding 50 Years of “Università Politecnica delle Marche”
Autore/i: Capozucca, R.; Carbonari, S.; Clementi, F.; Cocchi, G.; Davi, F.; Dezi, L.; Gara, F.; Lancioni, G.; Lenci, S.; Mentrasti, L.; Ragni, L.; Serpilli, M.
Editore: Springer, Cham
Classificazione: 2 Contributo in Volume
Abstract: In recent years, Italy has been hit by earthquakes, causing significant damage to masonry and reinforced concrete (RC) structures. Especially, common buildings and ordinary structures in many small historical towns of Italian central regions, such as Marche, have suffered dramatic consequences and destruction. Dynamic analysis and seismic structural safety are important topics in civil engineering, which have been studied and deepened for many years by the researchers of the Structural Division of the Department of Civil and Building Engineering, and Architecture of UnivPM. The researches have been oriented towards the investigation of structures under seismic loads in order to improve the knowledge of the structural response under high actions, due to the soil dynamic movements and, thus, define adequate techniques to strengthen the damaged structures. In this paper we present a wide spectrum of main results of our research group, comprising experimental studies, vulnerability analysis and assessment of existing structures, new methods of modelling and theoretical approaches to define the dynamic behavior of structures, also in presence of damage. Finally, we show and discuss new prospects of research for safety, employing advanced techniques and materials to prevent collapse and/or relevant damages in structures.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/281739 Collegamento a IRIS

2019
Evidence of coupled soil-structure interaction and site response in continuous viaducts from ambient vibration tests
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Gara, Fabrizio; Regni, Marco; Roia, Davide; Carbonari, Sandro; Dezi, Francesca
Classificazione: 1 Contributo su Rivista
Abstract: The scope of this research was to identify the significance of soil-structure interaction and site response on the dynamic behaviour of continuous multispan reinforced concrete viaducts, based on ambient vibration measurements and numerical simulations, using finite element models. For this purpose, an 875 m long bridge, located in Central Italy, founded on piles in eluvial-colluvial soil deposit was instrumented and ambient vibration tests together with geophysical investigations were performed. Experimental modal properties were evaluated by means of the operational modal analysis on accelerometric data and the role of soil-structure interaction in the interpretation of tests was detected by means of finite element models characterised by different accuracy in addressing the interaction problem. In the soil-structure interaction models the local site condition in correspondence of each bridge piers (resulting from geotechnical and geophysical investigations) were taken into account in the definition of the soil-foundation impedances. Comparison between the experimental results obtained from ambient noise measurements on the free-field and on the bridge deck permits the identification of both the predominant period of the site and the fundamental periods of the structure. In addition, comparisons between results obtained from the different numerical models with the measured dynamic response of the viaduct, in terms of fundamental frequencies and mode shapes, allow the identification of the contribution of different soil-structure interaction aspects such as the pile-soil-pile interaction, the radiation problem, the pile cap embedment as well as the variability of the soil stratigraphy along the longitudinal direction of the viaduct.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/264148 Collegamento a IRIS

2019
Dynamic performance of a full-scale micropile group: Relevance of nonlinear behaviour of the soil adjacent to micropiles
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Capatti, M. C.; Dezi, F.; Carbonari, S.; Gara, F.
Classificazione: 1 Contributo su Rivista
Abstract: An extensive experimental in-situ campaign of dynamic tests carried out on a full-scale 2 x 2 group of inclined injected micropiles in alluvial soils is described in this paper. The campaign includes ambient vibration and impact load tests to investigate the dynamic behaviour of the soil-micropile system in the small strain range, and forced vibration tests to investigate the performance of the system in the nonlinear field. Accelerometers and geophones are adopted to acquire the dynamic response on the cap and the soil nerby the cap, while strain gauges are installed along the shaft of one micropile to capture the local curvatures and deflections. The influence of the micropile inclination on the translational and rotational behaviour of the group is evaluated. Moreover, the evolution of degradation phenomena such as the gap opening and slippage at the soil-micropile interface and the radial cracking of soil surrounding micropiles, are recognized, critically commenting the relevant effects on the fundamental frequencies and damping ratios of the system.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/270855 Collegamento a IRIS

2019
The Role of Soil-Structure Interaction in the Interpretation of Dynamic Tests on the “Chiaravalle viaduct”
Eccomas Proceedia COMPDYN (2019)
Autore/i: Carbonari, Sandro; Dezi, Francesca; Gara, Fabrizio
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper addresses the significance of soil-structure interaction on the dynamic behaviour of the “Chiaravalle viaduct”, based on ambient vibration measurements and numerical simula-tions. The viaduct is located in Central Italy and is founded on piles in an eluvial-colluvial soil deposit. Experimental modal properties are evaluated by means of the operational modal anal-ysis on accelerometric data from ambient excitation and the role of soil-structure interaction in the interpretation of tests is investigated by means of a refined finite element model of the via-duct. In the soil-structure interaction models the local site condition in correspondence of each bridge piers (resulting from geotechnical and geophysical investigations) are considered in the definition of the soil-foundations compliance. Comparison between the experimental and nu-merical results highlight the role of the pile-soil-pile interaction, the radiation problem, the pile cap embedment and the variability of the soil stratigraphy along the longitudinal direction of the viaduct in the interpretation of the experimental data.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/267577 Collegamento a IRIS

2018
Artificial neural networks for the evaluation of impedance functions of inclined pile groups
Numerical Methods in Geotechnical Engineering IX: Proceedings of the 9th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE 2018)
Autore/i: Franza, A.; Dejong, M. J.; Morici, M.; Carbonari, S.; Dezi, F.
Editore: CRC Press
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Recent works provided insights into the role of inclined piles on the dynamic response of structures. However, there is a lack of design tools that can be implemented to perform inertial soil-structure interaction analyses, in the framework of the sub-structure approach, bypassing the numerical modelling of the kinematic interaction problem. For this purpose, this paper presents the application of ANNs to the impedance functions of inclined pile groups. Firstly, the dataset required for the training and testing of the ANNs is obtained from a parametric investigation in which the frequency-dependent impedance functions of 2x2 pile groups rigidly connected at the head and embedded in homogeneous soil deposits are considered. A dimensional analysis of the problem is performed and soil-foundation systems with different geometric characteristic and properties (e.g. inclination angles, pile-soil stiffness ratios, pile length-to-diameter ratios) are investigated. Data, representing the target of the neural networks, are obtained through a numerical FE model developed by the authors. The main trends of impedances with the dimensionless parameters of the pile groups are inferred from the presented results. Subsequently, several ANNs consisting of two hidden layers are trained, tested, and validated to optimise the generalisation performance of the model. Results show that ANNs are able to capture the trends of the impedance functions of inclined pile groups on the basis of the adopted dimensionless parameters. In addition, the complexity of the ANN models achieving good performance confirms the need for advanced regression models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259403 Collegamento a IRIS

2018
Dynamic Test for the Model Calibration and Pier Damage Detection of an Existing R.C. Multispan Viaduct
The 2018 World Congress on Advances in Civil, Environmental and Materials Research (ACEM18) & The 2018 Structures Congress (Structures18)
Autore/i: Gara, F.; Carbonari, S.; Minnucci, L.; Regni, M.; Speranza, E.
Editore: Chan-Koon Choi
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents and discusses results of the dynamic tests performed on the Moscosi Bridge in Cingoli (Italy). The main scope of the tests is to evaluate the dynamic parameters of the bridge, such as the eigenfrequencies, the mode shapes and the relevant modal damping ratios, in order to characterize the structural behaviour before the execution of some required restoration works, providing (i) useful information for the development of the numerical model for the design and (ii) a benchmark for the evaluation of the retrofit effectiveness, by repeating tests after the retrofit. The dynamic characterization is obtained through the measurements of ambient vibrations, which are processed with the Covariance-driven Stochastic Subspace Identification. In addition, the dynamic response of the bridge subjected to a vehicle passages is registered and compared to that induced by the ambient excitations. First considerations seem to reveal the presence of the observed structural damage at the base of one pier.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259689 Collegamento a IRIS

2018
Dynamic Test Based Model Calibration of an Existing R.C. School Building
The 2018 World Congress on Advances in Civil, Environmental and Materials Research (ACEM18) & The 2018 Structures Congress (Structures18)
Autore/i: Speranza, E.; Gara, F.; Carbonari, S.; Balducci, A.; Dezi, L.
Editore: Chang-Koon Choi
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper deals with the dynamic tests carried out on a school building seismically retrofitted with an innovative system that uses external steel dissipative towers. Before the retrofitting, ambient vibration tests were carried out with the aim of evaluating the modal parameters of the building including the contribution of nonstructural components to the global dynamic behavior of the structure. In particular, the contribution of non-structural components plays fundamental role in structural design because neglecting the infills in finite element models can produce macroscopic errors that may compromise the capacity of the models to predict the structural response of the structure when used for design purposes, such as for seismic retrofitting projects. In this context, the calibration of the finite element models (f.e. models) through experimental measurements plays a fundamental role in ensuring that the models reproduce with sufficient reliability the real behavior of the structure. After the building retrofitting, ambient vibration measurements were repeated to verify that variations in modal properties of the building, evaluated at very small input energy level, are in accordance with those expected from the numerical model. Furthermore, snap-back tests of the building were performed at different load levels to assess the dissipative capacity of the new structural system at greater input energy level.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259688 Collegamento a IRIS

2018
First processing and remarks on the observed damage to the churches of the Marche Region after the centre Italy earthquake 2016
Proceedings of the 8th International Conference on Building Resilience – ICBR Lisbon’2018 Risk and Resilience in Practice: Vulnerabilities, Displaced People, Local Communities and Heritages
Autore/i: Carbonari, Sandro; Dall’Asta, Andrea; Dezi, Luigino; Gara, Fabrizio; Leoni, Graziano; Morici, Michele; Prota, Andrea; Zona, Alessandro
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The seismic sequence that struck Central Italy in August-October 2016 seriously damaged many historical buildings of the Italian cultural heritage. In particular, churches were widely damaged due to intrinsic peculiarities of their structural systems, not able to develop an efficient box-like resisting mechanism. During seismic emergency, teams of experts carried out a massive survey of churches to assess both the occurred damage and their usability. Teams have been coordinated by the Department of Civil Protection and the Ministry of Cultural Heritage and Tourism. In this paper, a methodology for processing data recorded during inspections of churches of the Marche Region is proposed and used to analyse a limited dataset. Starting from the subdivision of the sample into homogeneous typologies, the most recurring damage mechanisms are identified. In addition, the global damage indexes of each churches are correlated with the relevant highest spectral pseudo acceleration at T=0.30s registered at the site as a consequence of the main shocks; this allows obtaining relationships between the seismic intensity and the expected damage. Finally, the overall damage occurred to churches of the sample is compared to that estimated through empirical models available in the literature.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/263175 Collegamento a IRIS

2018
Seismic behaviour of steel-concrete composite bridge decks
Steel and Steel-concrete composite structures in seismic areas: advances in research and design. The Research Project RP3 of the ReLUIS-DPC 2014-2018 – Activity carried out during years 2014-2016
Autore/i: Dezi, L.; Carbonari, S.; Dall’Asta, A.; Gara, F.; Minnucci, L.
Editore: Doppiavoce
Luogo di pubblicazione: Napoli
Classificazione: 2 Contributo in Volume
Abstract: The paper focuses on local problems relevant to the seismic response of steel-concrete composite bridge decks. In particular, the local mechanisms involved in the transferring of inertial forces from the slab to substructures are investigated with particular focus on the shear connection and the role of end cross beams. Firstly, open issues relevant to the seismic design and analysis of steel-concrete composite bridge decks are discussed and an overall state-of-art of the problem is depicted. Then, some case studies constituted by single span and two-spans I-shaped twin-girders and box girders steel-concrete composite bridges are selected and adopted to investigate local response of the decks subjected to seismic actions. Linear and non-linear applications are performed adopting different analysis methodologies in order to investigate stress resultants in the shear connection and to analyse the role of the end cross beams on the local transferring mechanisms of inertia forces; results of analyses on the selected case studies are shown and discussed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259405 Collegamento a IRIS

2018
A Lumped Parameter Model for Time-Domain Inertial Soil-Structure Interaction Analysis of Structures on Pile Foundations
EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS
Autore/i: Carbonari, S.; Morici, M.; Dezi, F.; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents a lumped parameter model for the approximation of the frequency-dependent dynamic stiffness of pile group foundations. The model can be implemented in commercial software to perform linear or nonlinear dynamic analyses of structures founded on piles taking into account the frequency dependent coupled roto-translational, vertical and torsional behaviour of the soil-foundation system. Closed-form formulas for estimating parameters of the model are proposed with reference to pile groups embedded in homogeneous soil deposits. These are calibrated with a nonlinear least square procedure, based on data provided by an extensive non-dimensional parametric analysis performed with a model previously developed by the authors. Pile groups with square layout and different number of piles embedded in soft and stiff soils are considered. Formulas are overall well capable to reproduce parameters of the proposed lumped system that can be straightforwardly incorporated into inertial structural analyses to account for the dynamic behaviour of the soil-foundation system. Some applications on typical bridge piers are finally presented to show examples of practical use of the proposed model. Results demonstrate the capability of the proposed lumped system as well as the formulas efficiency in approximating impedances of pile groups and the relevant effect on the response of the superstructure.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259406 Collegamento a IRIS

2018
Effect of Environmental Conditions on the Modal Response of a 10-Story Reinforced Concrete Tower
SHOCK AND VIBRATION
Autore/i: REGNI, MARCO; AREZZO, DAVIDE; Carbonari, S.; Gara, F.; Zonta, D.
Classificazione: 1 Contributo su Rivista
Abstract: We analyse the effect of temperature and wind velocity on the natural frequencies and modal damping ratios of the Faculty of Engineering Tower at the Universit`a Politecnica delle Marche, a 10-story reinforced concrete frame building, permanently monitored with low-noise accelerometers. The data recorded over the first 5 months of monitoring demonstrate that temperature variations and wind intensity have a clear effect on the first three natural frequencies and the corresponding damping ratios. Temperature is positively correlated to the first and second frequencies, corresponding to shear displacement modes and negatively correlated to the third frequency, corresponding to a torsional mode. All frequencies are positively correlated to wind velocity and changes in damping ratios are inversely correlated to any change in frequency. A mechanical explanation of these phenomena is offered, based on a critical review of literature case studies. These results suggest that using changes in modal parameters for damage detection always requires accurate knowledge of the correlation between modal parameters and environmental quantities (temperature, humidity, and wind velocity), an information which is only available through long-term continuous monitoring of the structural response.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259024 Collegamento a IRIS

2018
Effects of environmental conditions on the dynamic properties of a 10-storey r.c. square tower
EESMS 2018 - Environmental, Energy, and Structural Monitoring Systems, Proceedings
Autore/i: Arezzo, Davide; Regni, Marco; Carbonari, Sandro; Gara, Fabrizio
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259402 Collegamento a IRIS

2018
Soil-foundation compliance evidence of the “Chiaravalle viaduct”
Lecture Notes in Civil Engineering, 2018
Autore/i: Regni, Marco; Gara, Fabrizio; Francesca, Dezi; Davide, Roia; Carbonari, Sandro
Editore: Springer
Classificazione: 2 Contributo in Volume
Abstract: This paper describes some notable aspects demonstrating the contribution of the soil-foundation compliance on the measured dynamic response of the Chiaravalle viaduct subjected to ambient excitations. The viaduct, linking the SS76 with the airport of Ancona (in Central Italy), is 875 m long and consists of four r.c. kinematic chains separated by joints. The deck is constituted by three beams supported by column bent piers constituted by two circular r.c. columns founded on a continuous footing on six concrete piles. Ambient vibration measurements have been performed to determine experimental natural frequencies and mode shapes of the viaduct before a scheduled seismic rehabilitation of the structure; data have been used to calibrate a numerical model for the retrofit design. Experimental modal properties are evaluated by means of Operational Modal Analysis; due to the great length of the viaduct, different configurations of sensors placed on the deck are used to evaluate the overall behavior of the viaduct and the Pre Global Estimation Re-scaling method is adopted in order to merge the different parts of mode shapes relevant to each configuration. Furthermore, with reference to the transverse behaviour, some tests are performed in correspondence of one pier, measuring accelerations of the foundation cap (both translational and rotational components) and the pier bent, in order to identify contribution to the transverse modal displacement due to the elastic deflection of the pier and the foundation rocking. Results of dynamic tests are interpreted through a 3D Finite Element model of the viaduct. Firstly, a conventional fixed base model is considered, then a model including the Soil-Structure Interaction problem is developed in order to improve consistency between numerical and experimental results. The numerical model including Soil-Structure Interaction is able to capture the foundation rocking, experimentally detected, and provides modal parameters in good agreement with the experimental ones.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251324 Collegamento a IRIS

2018
Full scale experimental assessment of the dynamic horizontal behavior of micropiles in alluvial silty soils
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Capatti, M. C.; Dezi, F.; Carbonari, S.; Gara, F.
Classificazione: 1 Contributo su Rivista
Abstract: The paper deals with an extensive experimental campaign of dynamic tests performed on full-scale vertical injected and not injected micropiles embedded in alluvial soils. The experimentation includes ambient vibration and impact load tests to investigate the dynamic behaviour of the soil-micropile system in very small and small-medium strain ranges, as well as snap back tests to investigate the evolution of the post-elastic response of the system. Micropiles are instrumented with strain gauges along the shaft, accelerometers and displacement transducers at the head. Modalities and results of the different performed tests are presented, focusing on the role of high pressure injections on the dynamic behaviour of the system, on the development of non-linear soil-pile phenomena, and, finally, on the evaluation of effectiveness of the different testing procedures to capture the dynamic response of soil-micropile systems. Ambient vibration test revealed to be a versatile method to identify the dynamic properties of soil-micropile systems, although it requires demanding post-processing techniques of data. Impact load test is faster to perform and easier to post process. Free vibration test proved to be relatively simple to perform and able to catch the dynamic non-linear behaviour of soil-micropile systems.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/258773 Collegamento a IRIS

2018
Shear connection local problems in the seismic design of steel-concrete composite decks
Lecture Notes in Civil Engineering
Autore/i: CARBONARI, SANDRO; GARA, Fabrizio; Dall’Asta, A.; DEZI, LUIGINO
Editore: Springer, Cham
Classificazione: 2 Contributo in Volume
Abstract: This paper investigates local problems involved in the transfer mechanisms of inertia forces acting at the level of the concrete slab of typical steel-concrete composite bridge decks. In detail, the behaviour of the shear connection, usually designed with only refer-ence to non-seismic loads at the ultimate limit state, is studied considering shear forces descending from both horizontal and trans-verse seismic actions. Some results concerning twin-girder steel-concrete composite bridge decks characterised by different static schemes are presented and the distribution of longitudinal and transverse forces acting on the shear connection is discussed. First results demonstrate the significance of properly considering seismic induced forces in the design of the steel-concrete shear connec-tion and support the need of further investigations.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240818 Collegamento a IRIS

2018
Dynamic in situ tests for the calibration of an infilled R.C. Building F.E. model
EESMS 2018 - Environmental, Energy, and Structural Monitoring Systems, Proceedings
Autore/i: Nicoletti, Vanni; Gara, Fabrizio; Regni, Marco; Carbonari, Sandro; Dezi, Luigino
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259399 Collegamento a IRIS

2018
A low cost wireless sensor node for building monitoring
EESMS 2018 - Environmental, Energy, and Structural Monitoring Systems, Proceedings
Autore/i: Valenti, S.; Conti, M.; Pierleoni, P.; Zappelli, L.; Belli, A.; Gara, F.; Carbonari, S.; Regni, M.
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/259400 Collegamento a IRIS

2017
Risposta sismica non lineare di pile da ponte fondate su gruppi di pali inclinati
Atti del 17° Convegno Nazionale – L’ingegneria sismica in Italia (ANIDIS 2017)
Autore/i: Michele, Morici; Sandro, Carbonari; Fabrizio, Gara; Francesca, Dezi; Graziano, Leoni
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Questo lavoro presenta i primi risultati di una ricerca orientata allo studio degli effetti della configurazione e dell’inclinazione dei pali sulla risposta sismica non lineare di pile da ponte. La metodologia di analisi, basata su un approccio alle sottostrutture, viene preventivamente presentata; il sistema terreno-fondazione è analizzato nel dominio delle frequenze adottando un modello numerico sviluppato dagli autori mentre l’analisi di interazione inerziale delle sovrastrutture è svolta nel dominio del tempo per coglierne il comportamento non lineare. La dipendenza dalla frequenza delle funzioni di impedenza del sistema terreno-fondazione è approssimata nel dominio del tempo, attraverso un opportuno modello a parametri concentrati. La procedura è applicata ad alcuni casi studio costituiti da pile da ponte singole fondate in depositi di terreno argilloso di modesta ed elevata rigidezza. Sono considerate fondazioni costituite da pali aventi diversa inclinazione e pile caratterizzate da diversi periodi fondamentali e momenti flettenti di snervamento delle sezioni trasversali di base, al fine di simulare sistemi con diverso comportamento elastoplastico. I risultati delle analisi evidenziano il ruolo chiave rivestito dal rocking di fondazione sulla risposta strutturale e dimostrano che le fondazioni con pali inclinati possono contribuire a ridurre gli spostamenti massimi della testa della pila e la domanda di duttilità.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251351 Collegamento a IRIS

2017
Prime Rielaborazioni Circa i Danni Rilevati alle Chiese delle Marche a Seguito del Terremoto del Centro Italia (2016)
Gruppo Nazionale di Geofisica della Terra Solida - 36° convegno nazionale - Trieste, 14-16 novembre 2017
Autore/i: Carbonari, S.; Dall’Asta, A.; Dezi, L.; Gara, F.; Leoni, G.; Morici, M.; Prota, A.; Zona, A.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Le chiese sono edifici con valore storico e artistico che presentano una diffusione capillare nel territorio dell’Italia centrale e costituiscono una componente importante del patrimonio culturale. Il corpo di fabbrica di una chiesa è costituito da sottosistemi strutturali ricorrenti quali la facciata, le pareti laterali, il transetto, l’abside, la navata centrale e laterali, che tendono ad esibire risposte sismiche spesso indipendenti Studi effettuati sui danni subiti dalle chiese a seguito degli eventi sismici del Friuli 1976 (Doglioni et al. 1994), di Umbria-Marche 1997 (Lagomarsino e Podestà 2004a,b), del Molise 2002 (Lagomarsino e Podestà 2004c) dell’Aquila 2009 (Lagomarsino 2012) e dell’Emilia 2012 (Indirli et al. 2012, Sorrentino et al. 2014) hanno mostrato come i meccanismi di danno presentino caratteristiche ricorrenti nonostante l’unicità di ogni corpo di fabbrica. Partendo dalle conoscenze maturate nei precedenti studi eseguiti a seguito di eventi sismici importanti, in questo lavoro gli autori hanno rielaborato i primi dati relativi al danneggiamento subito dal patrimonio culturale marchigiano con l’obiettivo finale di individuare le relazioni che intercorrono tra danno osservato e intensità di scuotimento..Lo studio, di carattere metodologico, prende in esame un sottoinsieme dei dai dati raccolti nella visita di circa 3600 chiese e intende principalmente mettere in evidenza i problemi connessi all'elaborazione di informazioni spesso non omogenee, proponendo alcune strategie per la loro interpretazione.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/258369 Collegamento a IRIS

2017
Lumped Parameter Models for Time Domain Soil-Structure Interaction Analysis: Consistent vs Simplified Formulations and Effects on the Linear and Nonlinear Superstructure Response
Proceedings of DISS_17 5th International Workshop on dynamic interaction of soil and structure
Autore/i: González, Francisco; Morici, Michele; Carbonari, Sandro; Dezi, Francesca; Chiara Capatti, Maria; Leoni, Graziano; Padrón, Luis A.; Aznárez, Juan J.; Maeso, Orlando
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Due to the frequency-dependency of soil-foundation impedances, the dynamic interaction analysis of linear and nonlinear systems in time domain according to the sub-structure approach requires the defi-nition of suitable Lumped Parameter Models (LPMs) with frequency independent parameters to simulate the soil-foundation compliance. This paper investigates effects on the superstructure response resulting from the use of different LPMs. In particular, consistent and simpli-fied LPMs are considered and the linear response of single bridge piers founded on different pile foundations is studied. The effectiveness of selected LPMs is evaluated using results obtained from a direct ap-proach in the frequency domain as benchmark. Results demonstrate that simplified models can be sufficient in most cases to obtain a relia-ble prediction of the superstructure response.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/258370 Collegamento a IRIS

2017
Un modello analitico per l’interazione cinematica di pali singoli inclinati
Atti del 17° Convegno Nazionale – L’ingegneria sismica in Italia (ANIDIS 2017)
Autore/i: Sandro, Carbonari; Michele, Morici; Francesca, Dezi; Graziano, Leoni
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Questo lavoro presenta un modello analitico, basato sull’approccio di trave su suolo alla Winkler di tipo dinamico, per la valutazione delle sollecitazioni cinematiche in pali singoli inclinati dovute alla propagazione di onde sismiche nel terreno. I pali sono modellati con elementi trave di Eulero-Bernoulli e l’interazione con il terreno è colta sfruttando soluzioni analitiche disponibili in letteratura relative a strati di materiale viscoelastico soggetti a vibrazioni armoniche di dischi rigidi. Il comportamento accoppiato assiale e flessionale del palo è governato da un sistema di equazioni differenziali alle derivate totali, con le relative condizioni al contorno, che è risolto, con riferimento al caso del palo infisso in un deposito di terreno omogeneo, sfruttando le matrici esponenziali. Alcune applicazioni dimostrano, dal confronto dei risultati con quelli ottenuti da formulazioni rigorose agli elementi di contorno, che il modello proposto, caratterizzato da un basso onere computazionale, è capace di predire in modo accurato le sollecitazioni che si sviluppano in pali inclinati soggetti ad azioni sismiche.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251349 Collegamento a IRIS

2017
An innovative seismic protection system for existing buildings: external dissipative towers
Proceedings of the 16th World Conf. on Earthquake Engineering, WCEE 2017
Autore/i: Gioiella, L.; Balducci, A.; Carbonari, S.; Gara, F.; Dezi, L.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A common technique for the retrofit of existing structure is based on the installation of dissipative devices connecting adjacent storeys of buildings in either diagonal or chevron brace configurations. This type of damping system may present some disadvantages like the increment of axial forces in columns, which may leads to premature local failures, or some feasibility limits on the strengthening of the existing foundations at the base of the bracing system. In addition, indirect costs related to the interruption of the building utilization during execution of the retrofit can be very demanding, in particular for strategic buildings, such as hospitals or schools. Most of previous problems can be overcome by placing the dissipative bracings and the relevant foundations outside the building; systems with external dampers can be grouped into three main categories, depending on the kinematic behaviour of the system, which is a function of the arrangement of dampers and bracings. Recently, some applications have been developed by proposing a new configuration exploiting the rocking motion of a stiff external tower. This paper deals with this innovative system for seismic protection of existing buildings, especially strategic ones, patented as “Dissipative Towers”. The protection system is based on the structural coupling of the building with new steel truss towers constructed externally and then rigidly connected to the building floors by means of steel elements; the towers are erected over a rigid r.c. thick base plate that is restrained to the foundation cap with a spherical hinge located in central position of the base slab. The towers are equipped with dissipative devices connecting the corners of the two plates; the effectiveness of the dampers is enhanced by the use of articulated quadrangles which amplify the vertical displacements of the devices. The efficiency of the system is so high that usually it is designed to satisfy the immediate occupancy limit state even for high intensity earthquakes. The above system is applied to the retrofit of an existing school building in Italy, constituted by different blocks made of reinforced concrete frames. The seismic rehabilitation is obtained by suitably positioning external dissipative towers and eliminating expansion joints between adjacent blocks. The towers allow a high level of seismic protection at the ultimate limit state, with a significant reduction of horizontal displacements and accelerations. Moreover also the shear actions resisted by the existing frame are significantly reduced by the "Dissipative Towers". The seismic protection is achieved with a moderate economic impact due to the elimination of indirect costs related to the arrangement of internal spaces, interruption and/or relocation of activities.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/247090 Collegamento a IRIS

2017
Effetti del non sincronismo del moto sismico indotto da effetti di sito e dalla non linearità del terreno sulla risposta sismica di ponti fondati su pali
Atti del 17° Convegno Nazionale – L’ingegneria sismica in Italia (ANIDIS 2017)
Autore/i: Maria Chiara Capatti, ; Giuseppe, Tropeano; Michele, Morici; Sandro, Carbonari; Francesca, Dezi; Graziano, Leoni; Francesco, Silvestri
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Questo lavoro intende investigare gli effetti dell’asincronismo del moto sismico indotto da effetti di sito e dal comportamento non lineare del terreno sulla risposta sismica di lunghi viadotti multicampata con fondazioni su pali. In particolare, è stato esaminato un caso studio rappresentato da un viadotto fondato in un deposito di argilla tenera su substrato roccioso rigido, caratterizzato da una morfologia a cuneo. Il moto di riferimento su bedrock affiorante è costituito da un set di accelerogrammi reali e l’analisi di risposta sismica è stata effettuata con diversi metodi di analisi. Nelle analisi si è inoltre tenuto conto dell’interazione terreno-fondazione-struttura, utilizzando il metodo delle sottostrutture: in particolare l’analisi di interazione cinematica è stata formulata nel dominio delle frequenze, e sono poi stati utilizzati appropriati modelli a parametri concentrati per riprodurre il comportamento dipendente dalla frequenza del sistema terreno-fondazione nelle analisi non lineari di interazione inerziale della sovrastruttura. I risultati delle analisi, eseguite considerando sia moto sincrono che asincrono, hanno messo in luce la rilevanza della configurazione del deposito, del comportamento non lineare del terreno e dell’interazione terreno-fondazione-struttura sulla risposta sismica di viadotti fondati su pali.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251348 Collegamento a IRIS

2017
The Role of End Cross-beams on the Distribution of Seismic Induced Shear Actions on the Shear Connection in Steel-Concrete Composite Bridge Decks
Atti delle XXVI Giornate Italiane della Costruzione in Acciaio
Autore/i: Sandro, Carbonari; Lucia, Minnucci; Fabrizio, Gara; Luigino, Dezi; Andrea, Dall'Asta
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper focuses on local problems arising in the shear connection of typical steel-concrete com-posite bridge decks subjected to seismic actions. In detail, a case study constituted by an I-shaped twin-girder simply supported steel concrete composite deck is considered and the distribution of forces on the shear connection along the beams is presented, focusing on the role of end cross-beams. After a brief survey of the results obtained in previous researches by the authors, aimed at justifying the adopted analysis methodology, results of static equivalent seismic analyses of the se-lected case studies are shown and discussed, considering end cross-beams of different typology and stiffness. Results demonstrate the key role played by end cross-beams on the distribution of seismic actions on the shear connection.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251353 Collegamento a IRIS

2017
Validazione di un modello 3D per l’interazione dinamica terreno-struttura mediante prove in sito su fondazioni profonde
Atti del 17° Convegno Nazionale – L’ingegneria sismica in Italia (ANIDIS 2017)
Autore/i: Maria Chiara Capatti, ; Sandro, Carbonari; Francesca, Dezi; Fabrizio, Gara; Graziano, Leoni; Michele, Morici
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In questo articolo viene presentata e discussa la duplice validazione di un modello numerico per l’interazione dinamica terreno-fondazione-struttura nel caso di fondazioni profonde. Il modello, originariamente sviluppato per gruppi di pali verticali in terreni stratificati, e recentemente aggiornato per tener conto dell’inclinazione dei pali, considera l’interazione terreno-palificata e lo smorzamento per radiazione attraverso funzioni elastodinamiche di Green. La validazione è basata su dati sperimentali ottenuti attraverso due distinte campagne sperimentali. La prima campagna prove riguarda tre pali in acciaio vibro-infissi in ambiente marino, sui quali sono state eseguite prove di impatto e prove di snap-back, misurando le deformazioni lungo il palo sorgente e le accelerazioni in testa al palo sorgente e a quelli riceventi. Il secondo gruppo di dati sperimentali è stato ottenuto durante una recente campagna prove su due micropali singoli verticali e su un gruppo di tre micropali inclinati in terreno limoso alluvionale, durante la quale sono state eseguite prove di vibrazioni ambientali e di impatto, prove di snap-back e prove in condizioni di vibrazioni forzate. Attraverso il confronto tra dati numerici e sperimentali in termini di impedenza del sistema, si discute la capacità previsionale del modello nel simulare il fenomeno dell’interazione palo terreno al variare della tipologia di fondazione profonda.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251352 Collegamento a IRIS

2017
Prime analisi e considerazioni circa i danni rilevati al patrimonio culturale delle Marche a valle del terremoto del Centroitalia (2016)
Atti del 17° Convegno Nazionale – L’ingegneria sismica in Italia (ANIDIS 2017)
Autore/i: Sandro, Carbonari; Alessandro, Catanzaro; Valerio, D’Agostino; Andrea, Dall’Asta; Luigino, Dezi; Fabrizio, Gara; Graziano, Leoni; Michele, Morici; Andrea, Prota; Alessandro, Zona
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: La sequenza sismica che ha interessato l’Italia centrale a partire dal 24 Agosto 2016 ha provocato danni anche di grave entità a molti edifici di importanza storica e artistica. In particolare, per le peculiarità degli impianti strutturali incapaci di sviluppare un meccanismo resistente scatolare, le chiese sono state la tipologia di edifici storici maggiormente colpita. A seguito dell’emergenza sismica, squadre composte da tecnici esperti hanno eseguito sopralluoghi sulle chiese segnalate con il fine di valutare sia l’entità del danno che lo stato di sicurezza. Le squadre sono state coordinate dal Dipartimento di Protezione Civile (DPC) e dal Ministero dei Beni e delle Attività Culturali e del Turismo (MiBACT), tramite le strutture operanti all'interno della direzione di comando e controllo (Dicomac) e le sedi regionali del MiBACT. Nel presente lavoro, i dati registrati nelle schede A-DC compilate durante i sopralluoghi sono stati rielaborati per un campione di chiese della regione Marche. Operando sul campione si propone una metodologia di analisi che potrà in futuro applicarsi alla totalità dei dati. Partendo dalla suddivisione del campione in tipologie omogenee, sono stati analizzati i meccanismi di danno più ricorrenti. In aggiunta, gli indici di danno globali di ogni chiesa sono stati correlati con i massimi valori di Pseudo Accelerazione Spettrale a 0.30s registrati in sito in conseguenza delle maggiori scosse, nel tentativo di derivare una relazione tra intensità di scuotimento e danno atteso. Infine i danni rilevati nel campione sono stati confrontati con quelli forniti dai modelli empirici di vulnerabilità messi a punto sulla scorta dei dati registrati a seguito del terremoto Umbria-Marche 1997.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251347 Collegamento a IRIS

2017
Assessment survey of public school buildings after August 2016 Italy earthquake: preliminary results
Proceedings of the 16th World Conference on Earthquake Engineering (16WCEE)
Autore/i: Abruzzese, D.; Bergami, A.; Biondi, S.; Camata, G.; Canciani, M.; Carbonari, S.; Cimino, A.; Dall’Asta, A.; Dezi, F.; Dezi, L.; Di Fabio, F.; Ferracuti, B.; Fiorentino, G.; Forte, A.; Fragiacomo, M.; Gara, F.; Ianniruberto, U.; Imperatore, S.; Lavorato, D.; Leoni, G.; Liberatore, D.; Liberatore, L.; Mannella, A.; Martinelli, A.; Mutignani, C.; Nuti, C.; Paolacci, F.; Pagano, E.; Rasulo, A.; Santini, S.; Sorrentino, L.; Vanzi, I.; Zucconi, M.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/247082 Collegamento a IRIS

2017
Soil-structure interaction effects in single bridge piers founded on inclined pile groups
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: CARBONARI, SANDRO; Morici, Michele; Dezi, Francesca; GARA, Fabrizio; Leoni, Graziano
Classificazione: 1 Contributo su Rivista
Abstract: This paper investigates the seismic response of bridge piers founded on inclined pile groups in different soil deposits, evaluating effects of soil-structure interaction induced by different pile group geometries and piles inclinations. Analyses are performed in the frequency domain by means of the direct approach taking advantage of a numerical model developed by the authors for the analysis of inclined pile groups. Both the superstructure and piles are modelled with beam elements and the soil is schematized as a visco-elastic medium constituted by independent infinite horizontal layers. The soil-pile and the pile-soil-pile interaction are captured in the frequency domain by means of elastodynamic Green’s functions that also allow including the hysteretic and radiation damping. The significance of kinematic stress resultants in piles, the foundation filtering effect and the rotational component of the input motion due to the coupled roto-translational behaviour of the soil-foundation system are also investigated; to this purpose kinematic interaction analyses are performed. These analyses revealed essential for the understanding of the general phenomena governing the dynamic response of the whole soil-foundation-superstructure systems. Results of numerical investigations highlight that conventional design approaches suggested by codes do not provide reliable predictions of the superstructure displacements and stress resultants.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240768 Collegamento a IRIS

2017
A simplified elastic analysis of tunnel-piled structure interaction
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
Autore/i: Franza, Andrea; Marshall, Alec M.; Haji, Twana; Abdelatif, Amged O.; CARBONARI, SANDRO; Morici, Michele
Classificazione: 1 Contributo su Rivista
Abstract: In urban areas, engineers often need to assess tunnelling-induced displacements of piled structures and the resulting potential for damage. This paper presents an elastic study of tunnel-pile-structure interaction through Winkler-based Two-Stage Analysis Methods (TSAMs), focusing on structural displacements resulting from tunnel excavation beneath piled frames or simple equivalent beams. Comparison of results with 3D finite element analyses shows that the simple TSAM models are able to provide a good assessment of tunnelling-induced building displacements. Parametric analyses highlight the role of tunnel-pile interaction and the superstructure (stiffness, configuration, and pile-structure connections) in the global response of the tunnel-soil-building system. In particular, the effect that key parameters have on deflection ratios and horizontal strains are investigated. Results illustrate how piled foundations increase the risk of structural damage compared to shallow foundations, whereas structural stiffness can reduce building deformations. Flexural deformations are predominately induced by tunnel excavations beneath piles whereas horizontal strains at the ground level are negligible when a continuous foundation is included. Furthermore, it is illustrated that results based on buildings modelled as equivalent beams can differ considerably compared to when they are modelled as framed structures. Simple design charts are provided to estimate horizontal strains and deflection ratio modification factors based on newly defined relative axial and bending stiffness parameters which account for the presence of the piles.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240769 Collegamento a IRIS

2017
Simple Physical Models to Simulate the Behavior of Buckling-Type Marine Fenders
JOURNAL OF WATERWAY PORT COASTAL AND OCEAN ENGINEERING-ASCE
Autore/i: ANTOLLONI, GIULIA; CARBONARI, SANDRO; GARA, Fabrizio; LORENZONI, CARLO; MANCINELLI, ALESSANDRO
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents a simple physical model for the numerical simulation of the behavior of buckling-type marine fenders. The proposed model is characterized by four parameters and is derived starting from similarities between the unstable behavior of marine fenders and shallow arches. In this model, the large displacements solution expressing the relationship between the model displacements and reaction force is determined in a nondimensional form, and the model parameters are calibrated to minimize residuals between real and predicted normalized reaction force–deflection curves. By considering an in-series arrangement of two elementary physical models, the approach can be also used to simulate the behavior of parallel-motion fenders. The proposed model can be directly implemented in commercial computer programs for structural analysis to study interactions arising between buckling-type marine fenders and flexible berthing structures. In this paper, the model effectiveness in capturing the behavior of fenders and parallel motions systems is evaluated through comparisons of results, both in terms of reaction force and absorbed energy, with data of real devices, obtained from three different manufacturers. Results demonstrate the model efficiency and suitability for reproducing the behavior of a wide range of devices.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/236277 Collegamento a IRIS

2017
Implications of non-synchronous excitation induced by nonlinear site amplification and of soil-structure interaction on the seismic response of multi-span bridges founded on piles
BULLETIN OF EARTHQUAKE ENGINEERING
Autore/i: CAPATTI, MARIA CHIARA; Tropeano, Giuseppe; Morici, Michele; CARBONARI, SANDRO; Dezi, Francesca; Leoni, Graziano; Silvestri, Francesco
Classificazione: 1 Contributo su Rivista
Abstract: This work investigates the effects of soil-structure interaction and spatial variability of seismic motion due to nonlinear site amplification on the seismic behaviour of long multi-span bridges founded on piles. An analysis framework able to include the spatial variation of ground motion induced by specific geological and geomorphological scenarios in the seismic soil-structure interaction analysis of long bridges is adopted, exploiting advantages of the substructure approach. The methodology is applied to a case study constituted by a pile-supported multi-span bridge founded in a soft clay deposit overlaying a stiff bedrock with three different configurations: horizontal, inclined and wedge-shaped. The reference input motion at the outcropping bedrock is represented by a set of real accelerograms and different seismic response models are used to compute site amplification effects, discussing the contribution to the free-field ground motion of both the two-dimensional configuration of the deposit and the nonlinear soil behaviour. The ground motions obtained from the different models are then used for computing the foundation input motion accounting for the pile-soil kinematic interaction; thereafter, inertial interaction analyses are performed on structural models with either fixed or compliant base, considering the non-synchronous seismic actions at the piers foundation. The results, compared in terms of piers head displacements, ductility demand and deck transverse bending moments, finally show the relative importance of bedrock morphology, soil nonlinearity and soil-structure interaction on the structural response.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251320 Collegamento a IRIS

2017
Nonlinear response of bridge piers on inclined pile groups: The role of rocking foundation input motion
Procedia Engineering
Autore/i: Carbonari, S.; Morici, M.; Dezi, F.; Leoni, G.
Editore: Elsevier Ltd
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents first results of an on-going research focused on the effects of piles layout and inclination on the nonlinear seismic response of bridge piers. The analysis methodology, based on the substructure approach, is firstly presented. The soil-foundation system is studied in the frequency domain according to a numerical model developed by the authors while the inertial interaction analysis of the superstructures is carried out in the time domain to capture the nonlinear structural behaviour. A suitable lumped parameter model is used to approximate the frequency dependent behaviour of the soil-foundation impedances in the time domain analyses. The procedure is applied to some case studies constituted by single bridge piers founded on medium stiff and soft clayed soil deposits. Pile groups with piles of different inclinations are considered, as well as piers with different fundamental periods and yielding bending moments of the base cross sections, to simulate systems with different ductility capacity. Analyses results show the key role of the foundation rocking on the superstructure response and demonstrate that inclined pile foundations may have a significant impact on the superstructure response, reducing the pier head displacements and ductility demand.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251326 Collegamento a IRIS

2017
Dynamic behaviour of a retrofitted school building subjected to the after-shock sequence of the 2016 Central Italy earthquake
Procedia Engineering
Autore/i: Gara, Fabrizio; Regni, Marco; Carbonari, Sandro; Balducci, Alessandro; Dezi, Luigino
Editore: Elsevier Ltd
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper deals with the dynamic behaviour of a 1960s school building in Camerino subjected to moderate earthquakes belonging to the after-shock sequence of the 2016 Central Italy earthquake. The school structure, constituted by RC frames, was seismically retrofitted by means of "Dissipative Towers", an innovative system based on the use of external stiff steel truss towers equipped with dissipative dampers. Modal properties of the building after the retrofit have been determined through ambient vibration tests. After the main shock of the 2016 Central Italy earthquake, the building was instrumented with low-noise accelerometers and the dynamic behaviour of the structure during several aftershocks was recorded. Firstly, a numerical finite element model of the building is developed and calibrated on the basis of the ambient vibration measurements; then the registered dynamic response of the structure for the highest aftershock event (among the registered ones) is compared with that obtained numerically with the calibrated model. Results demonstrate the good agreement of the registered and predicted response.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251328 Collegamento a IRIS

2017
Kinematic Stress Resultants in Inclined Single Piles Subjected to Propagating Seismic Waves: an Analytical Formulation
Computational Methods in Structural Dynamics and Earthquake Engineering
Autore/i: Carbonari, Sandro; Morici, M.; Dezi, F.; Leoni, G.
Editore: M. Papadrakakis, M. Fragiadakis eds.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents an analytical model, based on the beam-on-dynamic Winkler foundation approach, for the evaluation of the kinematic stress resultants in single inclined piles subjected to the propagation of seismic waves. The Euler-Bernoulli beam model is adopted for the pile whereas analytical solutions available in literature for viscoelastic layers undergoing harmonic vibrations of a rigid disk are used for the soil. The coupled flexural and axial behaviour of the pile is governed by a system of partial differential equations, with the relevant boundary condi-tions, that is solved analytically in terms of exponential matrices. The solution for piles embed-ded in a homogeneous soil deposit is presented. Some applications, including comparisons of results with those obtained from rigorous boundary element formulations, demonstrate that the model, characterised by a very low computational effort, is able to accurately predict stress re-sultants in inclined piles subjected to seismic loading.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251323 Collegamento a IRIS

2017
Erratum to: Implications of non-synchronous excitation induced by nonlinear site amplification and of soil-structure interaction on the seismic response of multi-span bridges founded on piles
BULLETIN OF EARTHQUAKE ENGINEERING
Autore/i: CAPATTI, MARIA CHIARA; Tropeano, Giuseppe; Morici, Michele; CARBONARI, SANDRO; Dezi, Francesca; Leoni, Graziano; Silvestri, Francesco
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251321 Collegamento a IRIS

2017
Micropile foundation subjected to dynamic lateral loading
Procedia Engineering
Autore/i: Capatti, M. C.; Roia, D.; Carbonari, S.; Dezi, F.
Editore: Elsevier Ltd
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Thanks to their ease of installation, even in access-restricted spaces, micropiles are increasingly adopted for the seismic rehabilitation of existing structures. Moreover, both vertical and inclined micropiles are often used as foundation system for new constructions, ground improvements and many other applications. In order to deepen the knowledge of the dynamic behavior of those systems under horizontal loading, an extensive experimental study was carried out in an alluvial silty soil deposit on two single vertical micropiles and on a group of four inclined micropiles connected at the head by a concrete cap. Several testing procedures are exploited, in order to investigate the dynamic behavior of micropiles under different loading conditions and increasing force level, with special attention on the role of execution techniques and foundation configuration.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/251327 Collegamento a IRIS

2016
A higher order finite element to analyse steel-concrete composite bridge decks
Proceedings of the 19th IABSE Congress
Autore/i: Carbonari, Sandro; Dezi, Luigino; Gara, Fabrizio; Leoni, Graziano
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents a novel interdependent interpolation finite element for a higher order beam model capable of capturing the shear-lag phenomenon and the overall shear deformability of composite beams. After a brief overview of the beam kinematics and of the differential solving equations, the stiffness matrix and the nodal forces to be used in a standard finite element procedure are derived in a consistent way by exploiting properties of exponential matrices ad their application in the solution of linear differential equation systems. Some comparisons with solutions obtained by using finite elements with polynomial interpolating functions demonstrate the capability of the new element.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240871 Collegamento a IRIS

2016
An innovative seismic protection system for existing buildings: External Dissipative Towers
Proceedings of the 19th Congress of IABSE, Challenges in Design and Construction of an Innovative and Sustainable Built Environment
Autore/i: Carbonari, S.; Dezi, L.; Gara, F.; Leoni, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240884 Collegamento a IRIS

2016
A numerical model for the dynamic analysis of inclined pile groups
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
Autore/i: Dezi, Francesca; CARBONARI, SANDRO; Morici, Michele
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents a numerical model for the dynamic analysis of pile groups with inclined piles in horizontally layered soil deposits. Piles are modelled with Euler–Bernoulli beams, while the soil is supposed to be constituted by independent infinite viscoelastic horizontal layers. The pile–soil–pile interaction as well as the hysteretic and geometric damping is taken into account by means of two-dimensional elastodynamic Green's functions. Piles cap is considered by introducing a rigid constraint; the condensation of the problem permits a consistent derivation of both the dynamic impedance matrix of the soil–foundation system and the foundation input motion. These quantities are those used to perform inertial soil–structure interaction analyses in the framework of the substructure approach. Furthermore, the model allows evaluating the kinematic stress resultants in piles resulting from waves propagating in the soil deposit, taking into account the pile–soil–pile interactions. The model validation is carried out by performing accuracy analyses and comparing results in terms of dynamic impedance functions, kinematic response parameters and pile stress resultants, with those furnished by 3D refined finite element models. To this purpose, classical elastodynamic solutions are adopted to define the soil–pile interaction problem. The model results in low computational demands without significant loss of precision, compared with more rigorous approaches or refined finite element models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227948 Collegamento a IRIS

2016
Experimental study on instrumented micropiles
EESMS 2016 - 2016 IEEE Workshop on Environmental, Energy, and Structural Monitoring Systems, Proceedings
Autore/i: Capatti, Maria Chiara; Carbonari, Sandro; Gara, Fabrizio; Roia, Davide; Dezi, Francesca
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In the present work, first steps of an extensive experimental study carried out on two vertical micropiles in alluvial silty soil are presented. One of the vertical micropiles is injected throughout valves a-manchèttes placed along the steel core of the shaft, while the other one is grouted with a unique global injection. Both of them are instrumented with several strain gauges along the shaft and an accelerometer at the head. The protection technique adopted to prevent damages on the strain gauges during micropile installation and high-pressure injections is also discussed. The main objectives of this experimental campaign are the monitoring of the modifications in the dynamic characteristics of the complex soil-micropile system due to execution techniques and construction stages, and the investigation of the dynamic response considering different kind of cyclic and dynamic loading. In particular, the effect of the high-pressure injections on the dynamic response of vertical micropiles is here investigated, by means of series of ambient vibrations and lateral impact loading tests. Experimental data of impact load tests are finally compared with results obtained from an analytical model.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240910 Collegamento a IRIS

2016
Current state of the dynamic monitoring of the "chiaravalle viaduct"
EESMS 2016 - 2016 IEEE Workshop on Environmental, Energy, and Structural Monitoring Systems, Proceedings
Autore/i: Roia, Davide; Regni, Marco; Gara, Fabrizio; Carbonari, Sandro; Dezi, Francesca
Editore: Institute of Electrical and Electronics Engineers Inc.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper describes some notable aspects regarding the dynamic monitoring planned for the Chiaravalle viaduct, linking SS76 and airport of Ancona in Falconara, in Italy. The viaduct is 875 m long and consists of four r.c. kinematic chains separated by joints. The deck is constituted by three beams supported by column bent piers constituted by two circular r.c. columns founded on a continuous footing on six concrete piles. The first purpose of the dynamic monitoring is to determine the experimental natural frequencies and mode shapes of the viaduct before a scheduled seismic rehabilitation. Then, comparison of the first results with those obtained after the retrofit of foundation and piers and finally after the substitution of the deck bearing, will contribute to evaluate efficiency of the executed works. Two different inputs are used for the dynamic tests, ambient and traffic vibrations. An Operational Modal Analysis is carried out starting from the collected data, using the Enhanced Frequency Domain Decomposition technique. Different sensor configurations are used to evaluate the overall behaviour of the viaduct. The Pre Global Estimation Re-scaling method is adopted in order to merge the different parts of mode shapes relevant to each configuration. Results of dynamic tests are interpreted through a 3D Finite Element model of the viaduct. Firstly, a conventional fixed base model is considered, then a model including the Soil-Structure Interaction phenomena is developed in order to improve consistency between numerical and experimental results. The modal parameters obtained by the model including Soil-Structure Interaction are in good agreement with those estimated experimentally.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240911 Collegamento a IRIS

2016
Analytical evaluation of impedances and kinematic response of inclined piles
ENGINEERING STRUCTURES
Autore/i: CARBONARI, SANDRO; MORICI, MICHELE; DEZI, FRANCESCA; Leoni, Graziano
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents an analytical model, based on the beam-on-dynamic Winkler foundation approach, for the evaluation of impedances and kinematic response of single inclined piles. The pile is modelled as a Euler–Bernoulli beam having a generic inclination and the soil–pile interaction is captured by defining soil impedances according to expressions available in the literature for viscoelastic layers undergoing harmonic vibrations of a rigid disk. The coupled flexural and axial behaviour of the pile is governed by a system of partial differential equations, with the relevant boundary conditions, that is solved analytically in terms of exponential matrices. The solution for piles embedded in layered soils is achieved according to the direct stiffness approach by using the analytical solutions derived for generic pile sections embedded in homogeneous soils. Expressions of both the soil-foundation impedance functions and the foundation input motion are derived. Some applications, including comparisons of results with those obtained from rigorous boundary element formulations, are performed to evaluate the model capabilities. Classical stiffness and damping coefficients, based on the propagation of shear and pressure waves in plane-strain condition, are used in the applications to account for the soil–pile interaction; anyway, different formulations can be easily implemented. Results of applications, concerning piles with different inclination in both stiff and soft soils, demonstrate that the model, characterised by a very low computational effort, is able to capture the response of inclined piles subjected to seismic loading. Furthermore, with reference to linear problems, the model allows the derivation of the pile stiffness matrix that can be implemented in commercial computer software based on the finite element approach.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/234290 Collegamento a IRIS

2015
Impedances of inclined piles: an analytical solution
Atti del 16° Convegno Nazionale – L’ingegneria sismica in Italia (ANIDIS 2015)
Autore/i: Carbonari, Sandro; Morici, Michele; Gara, Fabrizio; Dezi, Francesca; Leoni, Graziano
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents an analytical solution, based on the beam-on-dynamic Winkler foundation approach, for the evaluation of the dynamic impedances of inclined single piles. The Euler-Bernoulli beam model is adopted for the pile whereas analytical expressions available in literature for viscoelastic layers undergoing harmonic vibrations of a rigid disk are used for the soil. The system of partial differential equations, governing the coupled flexural and axial behaviour of the pile embedded in a homogenous soil layer, is solved analytically in terms of exponential matrices. By assuming non-homogeneous kinematic boundary conditions, the dynamic stiffness matrix of the soil-pile system is derived analytically. In the case of layered soils, the pile is discretized into segments within which soil properties are constant and the dynamic stiffness matrix of the system is obtained according to the direct stiffness approach assembling contributions of all segments. Expressions of the soil-foundation impedance functions are derived by the problem condensation. Comparisons of results with those obtained from rigorous boundary element formulations demonstrate that the model, characterised by a very low computational effort, is able to reproduce the dynamic compliance of the soil-pile system with a good level of accuracy.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227951 Collegamento a IRIS

2015
Seismic response of bridges accounting for soil-structure interaction effects and the non-synchronous ground motion due to 1D and 2D site analysis
Atti del 16° Convegno Nazionale – L’ingegneria sismica in Italia (ANIDIS 2015)
Autore/i: Capatti, Maria Chiara; Carbonari, Sandro; Morici, Michele; Dezi, Francesca; Leoni, Graziano; Silvestri, Francesco; Tropeano, Giuseppe
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This work focuses on the effects of soil-structure interaction and the spatial variability of seismic motion due to site effects on the seismic response of a multi-span viaduct on pile foundations. In particular, site effects induced in a soft clay deposit by an inclined bedrock layout are evaluated through different models, characterised by an increasing level of accuracy, which allows determining the free-field motion that is adopted to perform soil-structure interaction analyses in the frame of the substructure approach. The seismic input is represented at the outcropping bedrock by a set of suitably selected and scaled real accelerograms. After a brief presentation of the adopted numerical procedure, analyses results are presented focusing on both site and structural response. Amplifications effects obtained from simplified linear equivalent 1D and nonlinear 2D site response models are compared, discussing the applicability of the simplified approach. Structural responses, obtained by considering the non-synchronous motion resulting from the local stratigraphic conditions, in conjunction with soil-structure interaction effects, are shown in terms of piers displacement and ductility demands. Furthermore, the role of soil-structure interaction is clarified comparing results with those obtained from fixed base bridge models, proving that its contribution is more significant if the simplified model for site response is adopted.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/227950 Collegamento a IRIS

2015
The Rocca Roveresca of Senigallia: seismic vulnerability of the defensive walls
Accademia Nazionale dei Lincei, XXXIII giornata dell’ambiente, Resilienza delle città d’arte, Enhancing Resilience of historic cities to earthquakes
Autore/i: Dezi, Luigino; Carbonari, Sandro; Gara, Fabrizio; Dall’Asta, Andrea; Leoni, Graziano; Zona, Alessandro
Editore: Bardi Edizioni
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: With the advent of cannons in XV century, many defensive walls underwent retrofitting to improve their capac-ity to withstand shots of the new powerful weapons. New lines of walls were erected by filling the left space with rubble stone materials. The different strata are characterized by specific behaviours and by well definite discontinuity surfaces so that the assessment of seismic vulnerability of such kind of defensive walls requires the definition of tailored failure mechanisms. A study on the behavior of the walls of the Rocca Roveresca of Senigallia in Italy is presented. A linear finite element model is first developed in order to understand the dy-namic behavior of a generic portion of the wall and to detect the probable incipient failure mechanisms. A subsequent static nonlinear analysis is carried out to investigate the formation of the cracking layout and to detect the position of plastic hinges. The last analysis level is carried out by supposing the wall to behave as a set of rigid blocks constituting a kinematic chain subjected to a finite displacement field typical for the col-lapse situation by introducing the degradation of the behavior of the inner (the less consistent) stratum.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/233497 Collegamento a IRIS

2015
First insights on the effects of inclined pile foundations on the nonlinear seismic response of bridge piers
Proceedings of the 4th International Workshop on Dynamic Interaction of Soil and Structure (DISS_15)
Autore/i: Carbonari, Sandro; Dezi, Francesca; Leoni, Graziano; Morici, Michele
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents first results of a research focused on the effects of piles layout and inclination on the nonlinear seismic response of bridge piers. In particular, some case studies are analysed highlighting some interesting aspects of the research. The analysis methodology, based on the substructure approach, is firstly presented. The soil-foundation system is studied in the frequency domain according to a numerical model developed by the authors that allows computing the frequency dependent impedances of the soil-foundation system as well as the foundation input motion. The inertial interaction analysis of the super-structures are performed in the time domain to capture the nonlinear structural behaviour and a suitable lumped parameter model is used to approximate the frequency dependent behaviour of the soil-foundation impedances in the time domain analyses. The procedure is applied to some case studies constituted by single bridge piers founded on a soft clayed soil halfspace. Two pile group configurations, characterised by vertical and inclined piles are considered, as well as piers with differ-ent yielding bending moments of the base cross sections, to simulate systems with different ductility capacity. The linear behaviour of the systems is also investigated for comparison. Effects of soil-structure interaction are evaluated considering results of fixed base piers as benchmark; analyses demonstrate that inclined pile foundations may have a significant impact on the superstructure response, reducing the pier head displacements and ductility demand.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/235022 Collegamento a IRIS

2015
Effects of non-synchronous ground motion induced by site conditions on the seismic response of multi-span viaducts
Proceedings of the 6th International Conference on Earthquake Geotechnical Engineering (6ICEGE)
Autore/i: Capatti, M. C.; Carbonari, S.; Dezi, F.; Leoni, G.; Morici, M.; Silvestri, F.; Tropeano, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240826 Collegamento a IRIS

2015
Analytical solution for a new higher order steel-concrete composite beam model
Proceedings of ICASS2015 – Eighth International Conference on “Advances in Steel Structures”
Autore/i: Gara, Fabrizio; Carbonari, Sandro; Leoni, Graziano; Dezi, Luigino
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents an analytical solution of a composite beam model in which the constrained kinematics takes account of the overall shear deformability, warping of the slab cross section and of the steel beam, and partial shear interaction between slab and girder. The warping functions are obtained by considering the problem of unrestrained thin-walled members subjected to self-equilibrated elementary load schemes. The governing equations are derived from the balance condition imposed with the Virtual Work Theorem. The analytical solution of the governing differential equations is obtained exploiting exponential matrices. This method, furnishing the exact formulation of the solution without requiring any discretization of the beam, is used to determine the solution of the proposed applications according to the stiffness method, deriving the stiffness matrix and the reactions of fixed-end beams. Two case studies, i.e. a symmetric two span bridge deck subjected to a uniformly distributed load and to a point load, are presented; the comparisons with results obtained with a refined shell finite element model are very satisfactory.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/233486 Collegamento a IRIS

2014
Risposta sismica di pile fondate su gruppi di pali inclinati
Atti delle Giornate A.I.C.A.P. 2014
Autore/i: Morici M.; Carbonari S.; Dezi F.; Gara F.; Leoni G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Questo lavoro indaga la risposta sismica di pile da ponte fondate su gruppi di pali inclinati tenendo conto dell’interazione terreno-struttura e considerando gruppi di pali con differente geometria e caratterizzati da pali con diversa inclinazione. Le analisi di interazione sono eseguite ricorrendo al metodo per sottostrutture ed utilizzando, per le analisi di interazione cinematica delle palificate a pali inclinati, un modello numerico 3D agli elementi finiti sviluppato dagli autori. In particolare, i pali sono modellati con elementi trave mentre il terreno è schematizzato come un mezzo visco-elastico costituito da strati orizzontali indefiniti tra loro indipendenti. L’interazione palo terreno e palo-terreno-palo è colta nel dominio delle frequenze utilizzando funzioni elastodinamiche di Green che permettono implicitamente di tenere conto anche dello smorzamento geometrico e isteretico. Le sovrastrutture hanno un comportamento lineare e sono schematizzate con elementi trave. L’approccio per sottostrutture permette di indagare separatamente gli effetti cinematici ed inerziali in fondazione, al variare della geometria della palificata, e di evidenziare il contributo dell’interazione nella definizione del moto sismico per le analisi delle sovrastrutture (moto della fondazione). I risultati delle analisi permettono di esprimere delle prime considerazioni circa l'influenza della configurazione della palificata e dell'inclinazione dei pali sul comportamento strutturale delle pile (spostamenti e caratteristiche di sollecitazione) e sulla risposta delle fondazioni (massimi tagli e momenti flettenti nei pali dovuti all'interazione cinematica e inerziale).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212146 Collegamento a IRIS

2014
Seismic response of bridge piers founded on inclined pile groups
Proceedings of the Second European Conference on Earthquake Engineering
Autore/i: Morici M.; Carbonari S.; Dezi F.; Gara F.; Leoni G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper investigates the seismic response of bridge piers founded on inclined pile groups, evaluating effects of soil-structure interaction by considering different pile group geometries and piles inclinations. Analyses are performed by means of the direct approach taking advantage of a 3D numerical model developed by the authors for the analysis of inclined pile groups. In particular, both the superstructure and piles are modelled by means of beam elements and the soil is schematized as a visco-elastic medium constituted by independent infinite horizontal layers. The soil-pile and the pile-soil-pile interaction are captured in the frequency domain by means of elastodynamic Green’s functions that also allow including the hysteretic and radiation damping. In order to investigate kinematic stress resultants in piles and to evaluate the significance of the soil-foundation system filtering effect, kinematic interaction analyses of the soil-foundation systems are also performed by removing the superstructure mass from the models. The influence of key parameters such as the piles inclination and the group configuration on the structural behaviour (displacements and stress resultants) and on the foundation response (maximum shears and bending moments in piles) is discussed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212150 Collegamento a IRIS

2014
A 3D numerical model for the dynamic analysis of pile groups with inclined piles
EURODYN 2014: IX INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS
Autore/i: Morici M.; Carbonari S.; Dezi F.; Leoni G.
Editore: EUROPEAN ASSOC STRUCTURAL DYNAMICS, C/O LEHRSTUHL BAUMECHANIK, TECHNISCHE UNIV MUNCHEN, ARCISSTRASSE 21, MUNICH, D-80290, GERMANY
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a numerical model for the kinematic interaction analysis of inclined pile groups; piles are modelled with beam finite elements and the soil is schematized with independent horizontal infinite layers. The pile-soil-pile interaction and the radiation problem are accounted for by means of elastodynamic Green’s functions. Piles cap is considered by introducing a rigid constraint; the condensation of the problem permits a consistent and straightforward derivation of both the impedance functions and the foundation input motions which are necessary to perform the inertial soil-structure interaction analyses, according to the substructure approach. The model, which also allows evaluating the kinematic stress resultants in piles resulting from the propagation of seismic waves in the soil, is validated performing accuracy analyses and comparing results, in terms of dynamic impedance functions, kinematic response parameters and pile stress resultants, with those furnished by 3D refined finite element models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212147 Collegamento a IRIS

2014
Nonlinear seismic analysis of innovative steel frames with infill walls
Proceedings of the Twelfth International Conference on Computational Structures Technology
Autore/i: Leoni G.; Carbonari S.; Morici M.; Tassotti L.; Zona A.; Varelis G.E.; Dall’Asta A.
Editore: Civil-Comp Press
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper deals with seismic resistant systems constituted by steel frames with reinforced concrete infill walls. Some innovations to overcome major drawbacks of classical systems, basically conceived like reinforced concrete shear walls, are introduced. The new system is configured to control the formation of diagonal struts in the infill walls; the energy dissipation takes place only in the vertical elements of the steel frame subjected mainly to axial forces without involving the reinforcements of the infill walls. A tailored procedure for the capacity design of the system is outlined. A numerical model for the nonlinear analysis, obtained with beam element and nonlinear links, is thus presented. The comparison of results with those obtained with refined finite element models, in which the reinforced concrete wall and the steel members are modelled with shell finite elements, is carried out. The proposed model is able to capture the sequence of wall cracking and yielding of ductile side elements. Finally, the procedure is applied to a six-storey building in order to demonstrate the capability of the innovative system to develop the dissipative mechanism.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212151 Collegamento a IRIS

2014
Dynamic analysis of inclined piles
Atti del XXV Convegno Nazionale di Geotecnica (CNG)
Autore/i: Dezi F.; Morici M.; Carbonari S.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a numerical model for the kinematic interaction analysis of inclined pile groups; piles are modelled with beam finite elements and the soil is schematized with independent horizontal infinite layers. The pile-soil-pile interaction and the radiation problem are accounted for by means of elastodynamic Green’s functions. Piles cap is considered by introducing a rigid constraint; the condensation of the problem permits a consistent and straightforward derivation of both the impedance functions and the foundation input motions, which are necessary to perform the inertial soil-structure interaction analyses, according to the substructure approach. The model, which also allows evaluating the kinematic stress resultants in piles resulting from the propagation of seismic waves in the soil, is validated performing accuracy analyses and comparing results, in terms of dynamic impedance functions, kinematic response parameters and pile stress resultants, with those furnished by 3D refined finite element models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212144 Collegamento a IRIS

2014
The effect of tie beams on the kinematic response and impedence functions of monopile foundations
Proceedings of the Second European Conference on Earthquake Engineering
Autore/i: Capatti M.C.; Carbonari S.; Dezi F.; Gara F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper focuses on the effect of tie beams on the kinematic response and impedance functions of monopile foundations. Considering a foundation system of a regular framed structure, constituted by monopiles connected with tie beams, a representative portion of the foundation is isolated by suitably modelling its boundary conditions, and kinematic Soil-Structure Interaction analyses are performed exploiting the numerical formulation proposed by Dezi et al. (2009) for the soil-pile system modelling. The model assumes a linear behaviour for the pile and is able to include the soil non linearity in a linear equivalent manner; this allows formulating the problem in the frequency domain where elastodynamic Green’s functions are used to account for the soil-pile interaction and for both the hysteretic and radiation damping. Tie beams are included into the formulation and the problem is solved by means of the finite element approach. A non dimensional parametric investigation is performed by varying the main geometrical and mechanical parameters affecting the whole system response. Results are presented in terms of impedance functions and kinematic response parameters, focusing on the effects of the foundation tie beams on the system response.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212149 Collegamento a IRIS

2014
Design procedure and analysis of innovative steel frames with reinforced concrete infill walls
Proceedings of the EUROSTEEL2014
Autore/i: Leoni G.; Carbonari S.; Morici M.; Tassotti L.; Zona A.; Varelis G.E.; Dall’Asta A.
Editore: ECCS
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Steel frames with reinforced concrete infill walls (SRCWs) are earthquake-resistant hybrid systems classified as Type 1 in EN 1998-1where they are considered to behave essentially as reinforced concrete walls able of dissipating energy in the vertical steel sections and in the vertical reinforcements of the walls. In addition, detailing provisions are the same provided for reinforced concrete walls except for indications on the edge shear connections. In reality, their behaviour might be very different and characterised by a resisting system in which diagonal compression struts develop within the reinforced concrete infill walls, resulting in cracks in the tension diagonal and crushing in the compression diagonal. Such issues are strictly related to the lack of a specific capacity design procedure that allows controlling the formation of a proper dissipating mechanism. Refined analyses previously carried out on SRCW systems designed according to Eurocodes demonstrated an unsatisfactory fragile behaviour due to the severe damage occuring to concrete long before yielding of the ductile elements. The failure mechanism is generally characterised by yielding of the steel frame concentrated mainly in the elements near the bottom of the wall (more specifically at the connections of the horizontal to the vertical parts). The plastic deformation on the concrete infill walls concentrates in a diagonal path clearly indicating the distribution of cracking. In addition, localized plastic deformations are also present near the corners of the infill walls due to the local action of the first studs of the horizontal and vertical elements. The innovative system depicted in Figure 1b is proposed to overcome the previous critical aspects. The RC infill walls are not connected to the vertical columns where the energy dissipation is expected. The system is conceived to control the formation of diagonal struts in the infill walls and behaves as a latticed brace instead of a shear wall. The energy dissipation takes place only in the vertical elements of the steel frame subjected mainly to axial forces without involving the reinforcements of the infill walls. Detailing of the connection of the dissipating elements should allow their replacement and the possible use of buckling-restrained elements. The formation of the diagonal strut is ensured by joint stiffeners and bearing plates. The joint may be welded in shops allowing speeding up the erection phases. The stud connectors are not required to transfer shear forces but they are used to connect the infill and the frame together during the seismic shakings. In this paper an innovative SRCW system, conceived to overcome some critical aspects of systems designed according to Eurocodes, and the relevant design procedure are presented.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212152 Collegamento a IRIS

2014
Seismic response of reinforced concrete frames on monopile foundations
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: CARBONARI, SANDRO; Dezi, F.; GARA, Fabrizio; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The paper focuses on the effects of soil-structure interaction on the seismic response of reinforced concrete frames on monopile foundations connected by tie beams. Such systems are usually designed by considering fixed restraints at the column bases and the effects of the foundation compliance have not yet been investigated. The soil-foundation system is analysed in the frequency domain by means of a numerical model that allows obtaining the dynamic impedance functions of the system and the foundation input motion necessary for the subsequent nonlinear inertial soil-structure interaction analysis which is performed in the time domain. Tie beams with different stiffness and soil deposits characterised by three different profiles of shear wave velocity are considered. Results of incremental dynamic analyses carried out on frames with monopile foundations are compared with those obtained considering double-pile foundations and the fixed base assumption. Soil-structure interaction is found to affect considerably the response of frames on monopile foundations by increasing the structural deformation and modifying the evolution of the dissipative mechanisms. Analyses accounting for the actual soil-foundation system compliance and the foundation input motion may be crucial for a reliable prediction of the actual distribution of stresses in the superstructure and the foundation elements.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212137 Collegamento a IRIS

2014
A higher order steel-concrete composite beam model
ENGINEERING STRUCTURES
Autore/i: GARA, Fabrizio; CARBONARI, SANDRO; G., Leoni; DEZI, LUIGINO
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents a model for the analysis of composite beams in which the constrained kinematics encompasses the overall shear deformability, warping of the slab cross section and of the steel beam and partial shear interaction between slab and girder. The warping functions are obtained by considering the problem of unrestrained thin-walled members subjected to self-equilibrated elementary load schemes. The governing equations are derived, according to the stiffness method, both in the weak and strong forms starting from the Virtual Work theorem which makes it possible to consistently obtain the resultants of stresses, the applied forces and the inertia involved in the problem. The analytical solution is obtained from the governing differential equations and the relevant boundary conditions exploiting exponential matrices. Some simple applications show the capability of the model to accurately describe both the global behaviour of composite beams, in terms of displacements and stress resultants, and local effects, in terms of normal stresses. The comparisons with results obtained with a refined shell finite element model are very satisfactory.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/212143 Collegamento a IRIS

2013
A model for the dynamic analysis of inclined pile groups
Atti del XV Convegno ANIDIS
Autore/i: Morici, M.; Carbonari, S.; Dezi, F.
Editore: Padova University Press
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a numerical model for the kinematic interaction analysis of inclined pile groups; piles are modelled with beam finite elements and the soil is schematized with independent horizontal infinite layers. The pile-soil-pile interaction and the radiation problem are accounted for by means of elastodynamic Green’s functions. Piles cap is considered by introducing a rigid constraint; the condensation of the problem permits a consistent and straightforward derivation of both the impedance functions and the foundation input motion which are necessary to perform the inertial soil-structure interaction analyses, according to the substructure approach. The model validation is carried out comparing results, in terms of dynamic impedances, with those furnished by 3D refined finite element models. With reference to some case studies, basic considerations concerning the behaviour of inclined piles are made from the comparison of results obtained by considering vertical and inclined piles.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/163119 Collegamento a IRIS

2013
Lumped parameter model for the time-domain soil-structure interaction analysis of structures on pile foundations
Atti del XV Convegno ANIDIS
Autore/i: Dezi F.; Carbonari S.; Leoni G.
Editore: Padova University Press
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A lumped parameter model for the time domain inertial soil-structure interaction analysis is proposed with reference to square pile group foundations. Simplified formulas are presented for estimating its parameters. The model is able to reproduce the coupled rotational-translational behaviour of the soil-foundation system. Formulas are calibrated from results of an extensive non-dimensional parametric analysis considering head-bearing pile groups. The closed-form expressions may be readily adopted to define the compliant base restraints of a generic structure for the non linear dynamic analysis carried out with commercial software.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/163117 Collegamento a IRIS

2013
Soil-structure interaction effects on the seismic response of multi-span viaducts
Atti del XV Convegno ANIDIS
Autore/i: Carbonari S.; Morici M.; Dezi F.; Leoni G.
Editore: Padova University Press
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper focuses on the effects of soil-structure interaction in the seismic response of multi-span viaducts on pile foundations. Analyses are performed by means of the substructure approach: the soil-foundation systems are studied in the frequency domain to obtain the foundation input motion and the dynamic impedance functions; inertial interaction analyses are carried out in the time domain accounting for the material nonlinear behaviour. Suitable lumped parameter models are introduced to simulate the frequency dependent behaviour of the soil-foundation system. A specific procedure for selecting and scaling real ground motions is proposed and used for the definition of the spatial seismic input. The seismic response of bridges on compliant base is compared with that obtained from fixed base analyses discussing the significance of soil-structure interaction effects.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/163116 Collegamento a IRIS

2013
Seismic soil-structure-interaction of multi-span bridges with continuous deck
Proceedings of the International Conference on Earthquake Geotechnical Engineering From Case History to Practice In honour of Prof. Kenji Ishihara
Autore/i: Carbonari S.; Morici M.; Dezi F.; Leoni G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper focuses on the effects of soil-structure interaction in the seismic response of multi-span viaducts on pile foundations. Analyses are performed by means of the substructure approach: the soil-foundation systems are studied in the frequency domain to obtain the foundation input motion and the dynamic impedance functions; inertial interaction analyses are carried out in the time domain accounting for the material nonlinear behaviour. Suitable lumped parameter models are introduced to simulate the frequency dependent behaviour of the soil-foundation system. A specific procedure for selecting and scaling real ground motions is proposed and used for the definition of the spatial seismic input. The seismic response of bridges on compliant base is compared with that obtained from fixed base analyses discussing the significance of soil-structure interaction effects.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/163110 Collegamento a IRIS

2013
Empirical formulas to define LPMs for time-domain analysis of structures on pile foundations
Proceedings of the International Conference on Earthquake Geotechnical Engineering From Case History to Practice In honour of Prof. Kenji Ishihara
Autore/i: Dezi F.; Carbonari S.; Leoni G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A lumped parameter model for the time domain inertial soil-structure interaction analysis is proposed with reference to square pile group foundations. Simplified formulas are presented for estimating its parameters. The model is able to reproduce the coupled rotational-translational behaviour of the soil-foundation system. Formulas are calibrated from results of an extensive non-dimensional parametric analysis considering head-bearing pile groups. The closed-form expressions may be readily adopted to define the compliant base restraints of a generic structure for the non linear dynamic analysis carried out with commercial software.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/163112 Collegamento a IRIS

2013
Dynamic analysis of battered pile groups
Proceedings of the International Conference on Earthquake Geotechnical Engineering From Case History to Practice In honour of Prof. Kenji Ishihara
Autore/i: Carbonari S.; Morici M.; Dezi F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a numerical model for the kinematic interaction analysis of inclined pile groups; piles are modelled with beam finite elements and the soil is schematized with independent horizontal infinite layers. The pile-soil-pile interaction and the radiation problem are accounted for by means of elastodynamic Green’s functions. A rigid constraint is introduced to account for the pile cap and the problem condensation allows obtaining the dynamic impedance matrix of the soil-foundation system The model is validated comparing results, in terms of dynamic impedances, with those furnished by 3D refined finite element models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/163113 Collegamento a IRIS

2013
Interdependent interpolation element for shear deformable composite beams
Atti del XXIV Congresso C.T.A.
Autore/i: Carbonari S.; Dezi L.; Gara F.; Leoni G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents a novel interdependent interpolation finite element for a higher order beam capable of capturing shear-lag phenomenon and overall shear deformability of composite beams. After a brief overview of the beam kinematics and of the differential solving equations, the stiffness matrix and the nodal forces to be applied in a standard finite element procedure are derived in a consistent way by exploiting properties of exponential matrix ad their application in the solution of linear differential equation systems. Some comparisons with solutions obtained by using finite elements with polynomial interpolating functions demonstrate the capability of the new element.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/163559 Collegamento a IRIS

2013
Tests on two 18-years-old prestressed thin walled roof elements
ENGINEERING STRUCTURES
Autore/i: CARBONARI, SANDRO; GARA, Fabrizio; ROIA, DAVIDE; G., Leoni; DEZI, LUIGINO
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents the experimental tests carried out on two prestressed thin walled V-shaped elements, used over a period of 18 years as the roof of an industrial building and removed after having exhibited marked deflections and crack patterns. The experimental program, including material characterization, impact load and ultimate static load tests, is aimed at valuating the actual load carrying capacity of the elements. The survey of the elements geometry, with special attention to imperfections, is presented; then results of the impact load test, namely the fundamental frequencies and modal shapes of free vibration, are reported. Successively, the results of static load tests up to failure are discussed. Due to the small thickness of the cross section walls, second order effects strongly interact with the global failure mechanism. The combination of dynamic impact and ultimate static load tests allowed the calibration of an accurate finite element model, accounting for both mechanical and geometrical nonlinearities, capable to predict the behaviour of the elements up to collapse and useful to design repairing and strengthening works.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/86615 Collegamento a IRIS

2012
Effects of soil-foundation flexibility on the performance of reinforced concrete frame structures
Proceedings of the 2nd Int. Conf. on Performance Based Design in Earthquake Geotechnical Engineering, IIPBD
Autore/i: Dezi, F.; Carbonari, S.; Gara, F.; Leoni, G.
Editore: Pàtron Editore
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper focus on the effects of soil-structure interaction on the seismic response of reinforced concrete frames designed according to displacement-based approaches and founded on piles. The substructure method is adopted and 6-storeys 3-bays frames founded on 3 different two-layered soil deposits are considered. For each soil deposit two foundation typologies are adopted: mono-pile and double-pile foundations. Soil-structure interaction effects on the seismic response of the structures are evaluated both in the linear and nonlinear field by means of incremental dynamic analyses. Results, in terms of forces and displacements, are compared with those achieved from conventional fixed base analyses demonstrating that soil-structure interaction effects are more evident for moderate earthquakes, inducing early structural damages, and for soft soil deposits. For earthquakes of high intensity soil-structure interaction is less important. The mono-pile foundation, suitably designed in conjunction with stiff tie-beams, is able to guarantee an efficient degree of restraint at the base of columns, comparable with that provided by the double-pile foundation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/74916 Collegamento a IRIS

2012
Seismic response of reinforced concrete frames on pile foundations
Proceedings of the 18th IABSE Congress on Innovative Infrastructures – Towards Human Urbanism
Autore/i: Dezi F.; Carbonari S.; Gara F.; Leoni G.
Editore: IABSE-ETH Honggerberg
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper focus on the effects of soil-structure interaction on the seismic response of reinforced concrete frames founded on piles. The substructure method is adopted and 6-storeys 3-bays frames founded on 3 different two-layered soil deposits are considered. For each soil deposit two foundation typologies are adopted: mono-pile and double-pile foundations. Soil-structure interaction effects on the seismic nonlinear response of the structures are evaluated by means of incremental dynamic analyses. Results are compared with those achieved from fixed base analyses demonstrating that soil-structure interaction effects are more evident for moderate earthquakes, inducing early structural damages, and for soft soil deposits. The mono-pile foundation, suitably designed in conjunction with stiff tie-beams, is able to guarantee an efficient degree of restraint at the base of columns, comparable with that provided by the double-pile foundation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/82712 Collegamento a IRIS

2012
Seismic response of viaducts accounting for soil-structure interaction
Proceedings of the 15th World Conference on Earthquake Engineering
Autore/i: Carbonari S.; Morici M.; Dezi F.; Leoni G.; Nuti C.; Silvestri F.; Tropeano G.; Vanzi I.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A research was recently granted by the Italian Government to develop a comprehensive procedure to account for spatial variability of ground motion as well as soil-structure interaction in assessing the behaviour of bridges. This paper reports on the work-package relevant to the effects of soil-structure interaction. In the first section, a methodology to include the effects of soil-structure interaction in the nonlinear response of bridges is presented. Kinematic interaction analysis is performed in the frequency domain by means of a procedure accounting for radiation damping, soil-pile and pile-to-pile interaction; the non-linear inertial interaction analysis is performed in the time domain by using a finite element model of the superstructure. Suitable lumped parameter models are implemented to reproduce the frequency-dependent compliance of soil-foundation systems. In the second section, some results of nonlinear dynamic analyses performed on some bridges designed on soft soils by means of a direct displacement approach are presented.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85167 Collegamento a IRIS

2012
Effects of Soil-Structure Interaction on the Linear and Nonlinear Seismic Behaviour of Coupled Wall-Frame Systems
Dynamic Interaction of soil and structure (DISS_12)
Autore/i: Carbonari, Sandro; Dezi, Francesca; Gara, Fabrizio; Leoni, Graziano
Editore: Aracne
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The effects of Soil-Structure Interaction (SSI) on the response of coupled wall-frame structures on pile foundations are investigated. The analysis methodology based on the substructure method is re-called focusing on the modelling of pile group foundations. The iner-tial interaction analysis is performed in the time domain by using a fi-nite element model of the superstructure and suitable Lumped Pa-rameter Models (LPMs) are implemented to reproduce the frequency-dependent compliance of the soil-foundation systems. The effects of SSI are evaluated by considering realistic case studies consisting of 6-storey 4-bay wall-frame structures founded on piles. Moderate and strong seismic actions are simulated employing real and artificial earthquakes. The superstructure is assumed to behave linearly under moderate shakings; on the other hand, the nonlinear structural behav-iour is accounted for in the case of strong earthquakes. Comparisons of the results obtained considering compliant base and fixed base models are presented by addressing the effects of SSI on the main re-sponse quantities of linear and nonlinear structures. SSI effects on displacements, inter-storey drifts and base shears are discussed and, with reference to the nonlinear structures, effects on the ductility de-mand and the evolution of dissipative mechanisms are investigated by considering earthquakes with increasing intensity.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/225215 Collegamento a IRIS




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