Sandro CARBONARI

Pubblicazioni

Sandro CARBONARI

 

171 pubblicazioni classificate nel seguente modo:

Nr. doc. Classificazioni
114 4 Contributo in Atti di Convegno (Proceeding)
50 1 Contributo su Rivista
6 2 Contributo in Volume
1 8 Tesi di dottorato
Anno
Risorse
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

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
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, Sandro; Dezi, Luigino; Gara, Fabrizio; Leoni, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/240884 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

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
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
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

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
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
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, Sandro; 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
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
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

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

2014
Dynamic analysis of inclined piles
Atti del XXV Convegno Nazionale di Geotecnica (CNG)
Autore/i: Dezi, F.; Morici, M.; Carbonari, Sandro
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
Design procedure and analysis of innovative steel frames with reinforced concrete infill walls
Proceedings of the EUROSTEEL2014
Autore/i: Leoni, G.; Carbonari, Sandro; 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
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, Sandro; Dezi, F.; Gara, Fabrizio
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
Seismic response of bridge piers founded on inclined pile groups
Proceedings of the Second European Conference on Earthquake Engineering
Autore/i: Morici, M.; Carbonari, Sandro; Dezi, F.; Gara, Fabrizio; 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
Risposta sismica di pile fondate su gruppi di pali inclinati
Atti delle Giornate A.I.C.A.P. 2014
Autore/i: Morici, M.; Carbonari, Sandro; Dezi, F.; Gara, Fabrizio; 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
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, Sandro; 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
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

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 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, Sandro; 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

2013
A model for the dynamic analysis of inclined pile groups
Atti del XV Convegno ANIDIS
Autore/i: Morici, M.; Carbonari, Sandro; 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
Interdependent interpolation element for shear deformable composite beams
Atti del XXIV Congresso C.T.A.
Autore/i: Carbonari, Sandro; Dezi, Luigino; Gara, Fabrizio; 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
Soil-structure interaction effects on the seismic response of multi-span viaducts
Atti del XV Convegno ANIDIS
Autore/i: Carbonari, Sandro; 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
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, Sandro; 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
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, Sandro; 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, Sandro; 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
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, Sandro; 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
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
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, Sandro; Gara, Fabrizio; 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
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, Sandro; Gara, Fabrizio; 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 viaducts accounting for soil-structure interaction
Proceedings of the 15th World Conference on Earthquake Engineering
Autore/i: Carbonari, Sandro; 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

2012
Higher order model for the seismic response of bridge embankments
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Dezi, F.; Morici, M.; Carbonari, Sandro; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents a new higher order model for the dynamic analysis of embankments. By considering a Legendre polynomial expansion to describe the motion at a generic point of the embankment, the application of the Lagrange-D’Alembert principle in conjunction with a through-the-width closed-form integration allows reducing the 3D physical domain into a 2D analytical domain. 4-node isoparametric elements with linear interpolating functions are used to numerically solve the problem. The model is suitable for bridge embankments by introducing a kinematic rigid constraint to account for the presence of the abutment. The embankment frequency dependent impedances and the displacements to be imposed to the abutment in bridge seismic analyses are obtained by condensation. The model has been validated comparing results with those furnished by high-fidelity 3D finite element models. The application to the approach embankment of an instrumented bridge subjected to a severe earthquake has demonstrated the model capability to capture both occurrence and intensity of main response peaks, as well as the frequency content of the response.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85166 Collegamento a IRIS

2012
Nonlinear seismic behaviour of wall-frame dual systems accounting for soil-structure interactions
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
Autore/i: Carbonari, Sandro; Dezi, F.; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The aim of this paper is to study the effects of soil-structure interaction on the seismic response of coupled wall-frame structures on pile foundations designed according to modern seismic provisions. The analysis methodology based on the substructure method is recalled focusing on the modelling of pile group foundations. 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 the soil-foundation systems. The effects of SSI are evaluated by considering a realistic case study consisting of a 6-storey 4 bay wall-frame structure founded on piles. Different two-layered soil deposits are investigated by varying the layer thicknesses and properties. Artificial earthquakes are employed to simulate the earthquake input. Comparisons of the results obtained considering compliant base and fixed base models are presented by addressing the effects of soil-structure interaction on displacements, base shears, and ductility demand. The evolution of dissipative mechanisms and the relevant redistribution of shear between the wall and the frame are investigated by considering earthquakes with increasing intensity. Effects on the foundations are also shown by pointing out the importance of both kinematic and inertial interaction. Finally, the response of the structure to some real near-fault records is studied.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85163 Collegamento a IRIS

2012
Soil-structure interaction in the seismic response of an isolated three-span motorway overcrossing founded on piles
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Dezi, F.; Carbonari, Sandro; Tombari, A.; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The effects of soil-structure interaction on the seismic response of an isolated three span motorway overcrossing founded on piles are investigated by considering a real bridge located along the A14 Motorway in central Italy. The dynamic and mechanical properties of the soils are obtained from a comprehensive geotechnical characterization of the sites. Ten triplets of real accelerograms, defined at the outcropping bedrock, are adopted and processed by local response analyses to capture the site amplification effects and the free-field motions within the deposits. The soil-structure interaction effects are evaluated by means of the substructure method by comparing the seismic response of the structures with those obtained from conventional fixed base models. Analyses demonstrate that the soil-foundation dynamic compliance as well as the energy loss due to radiation damping dot not modify significantly the overall behaviour of the isolated bridges, while soil-structure interaction may increase deformations and forces on the isolation devices with respect to those obtained with fixed base models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85164 Collegamento a IRIS

2011
Risposta sismica di telai in calcestruzzo armato fondati su pali
Atti del XIV Convegno ANIDIS
Autore/i: Carbonari, Sandro; Dezi, F.; Gara, Fabrizio; Leoni, G.
Editore: Digilabs
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: ABSTRACT Questo lavoro presenta uno studio sugli effetti dell’interazione terreno-struttura nella risposta sismica di telai in calcestruzzo armato fondati su pali. Adottando un approccio per sottostrutture, sono stati studiati telai in calcestruzzo armato di 3 campate e 6 piani, fondati su 3 differenti depositi bistrato al di sopra di un substrato sismico. Per ciascun deposito sono state ipotizzate due tipologie di fondazione: mono-palo e bi-palo. Gli effetti dell’interazione sulla risposta delle strutture sia in campo elastico che post-elastico sono valutati per mezzo di analisi incrementali delle strutture a base deformabile. I risultati, in termini di forze e spostamenti, confrontati con quelli ottenuti da analisi convenzionali a base fissa, dimostrano che il ruolo dell’interazione terreno-struttura è più significativo per intensità sismiche moderate, che provocano il primo danneggiamento delle strutture, e per i depositi più deformabili. Per terremoti di alta intensità, l’interazione terreno-struttura gioca un ruolo minore. Il sistema mono-palo, opportunamente progettato insieme con gli elementi di collegamento, si è dimostrato capace di garantire un grado di vincolo alla base paragonabile a quello offerto dal sistema bi-palo.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63573 Collegamento a IRIS

2011
Indagini sperimentali su due tegoli in c.a.p. dopo 18 anni di esercizio
Atti del 26° Convegno nazionale “Giornate A.I.C.A.P.”
Autore/i: Carbonari, Sandro; Gara, Fabrizio; Roia, Davide; Leoni, G.; Dezi, Luigino
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: SOMMARIO In questo lavoro si presenta un’indagine sperimentale eseguita su due tegoli in c.a.p. con sezione a V utilizzati per circa 18 anni in copertura di un edificio industriale. I tegoli presentano quadri deformativi e fessurativi che hanno suggerito l’esecuzione di prove di carico statico spinte fino a rottura. Le prove sono state precedute dalla caratterizzazione dinamica dei tegoli con forzante impulsiva che ha permesso di determinare le frequenze proprie e i modi di vibrare. Per la caratterizzazione del calcestruzzo sono state eseguite prove a compressione su provini cubici e cilindrici ricavati da carote prelevate dai tegoli. I risultati sperimentali sono stati interpretati con un modello numerico non lineare agli elementi finiti che ha permesso di formulare alcune prime osservazioni sulla sensibilità del tegolo alle non linearità geometriche e meccaniche.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63577 Collegamento a IRIS

2011
Site effects and soil-structure interaction on an isolated highway overcrossing on pile foundations
Proceedings of the 5th International Conference on Earthquake Geotechnical Engineering, 5ICEGE
Autore/i: Tombari, A.; Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: Chilean Geotechnical Society
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper the effects of soil-structure interaction on the dynamic response of isolated overcrossings are investigated with reference to a case study, constituted by a real highway bridge. An accurate geotechnical characterization of the site is available from which the dynamic and mechanical properties of the soil are obtained. The seismic input is defined at the outcropping bedrock by means of real accelerograms and local response analyses are performed to compute the free-field input motions accounting for the non linear soil behaviour. The soil-structure interaction effects are evaluated on isolated and non-isolated bridges by comparing the seismic response of the structure with that obtained from a conventional fixed base model. Results demonstrate that the non-isolated bridge is more sensitive to soil-structure interaction effects, particularly in the transverse direction, where the pier stiffness is very high. Nevertheless, on the isolated bridge, soil-structure interaction produces an increase of the total shear strain in the isolators that should be taken in account in the verifications.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85348 Collegamento a IRIS

2011
Soil-structure interaction in the seismic response of the isolated overcrossings of the A14 motorway section Cattolica-Senigallia
Atti del XIV Convegno ANIDIS
Autore/i: Tombari, A.; Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: Digilabs
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The effects of soil-structure interaction on the seismic response of isolated overcrossings are investigated by considering five real bridges that will be built along the A14 Motorway in the Marche Region. The dynamic and mechanical properties of the soils are obtained from a comprehensive geotechnical characterization. The seismic input is constituted by ten triplets of real accelerograms that are processed by a local response analyses to capture the site amplification effects and the free-field motions within the deposits. The soil-structure interaction effects are evaluated by comparing the seismic response of the structure with that obtained from a conventional fixed base model. As for the overall behaviour, analyses demonstrate that the isolated bridges are not sensitive to soil-structure interaction that do not modify the fundamental periods of the structures. Isolation units are also slightly sensitive to the soil structure interaction that increases deformations and forces of about 10% with respect to those obtained with fixed base models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85360 Collegamento a IRIS

2011
Dynamic stiffness and kinematic response of bridge embankments
Atti del XIV Convegno ANIDIS
Autore/i: Dezi, F.; Morici, M.; Carbonari, Sandro; Leoni, G.
Editore: Digilabs
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Dynamic stiffness of bridge embankments and their kinematic response when subjected to harmonic unit motions at the base are investigated. These quantities furnish global information on the seismic response of embankments that may be used, according to a substructure approach, to include effects of abutment-embankment interaction in the seismic analysis of bridges. Embankments with trapezoidal cross sections of different height and with different length and longitudinal slope are considered in the analyses which are performed in the frequency domain by means of a 2D higher order model developed by the authors. The soil material properties and the inclination of the cross section slopes are selected within common ranges in practical applications. The presence of rigid abutment is considered. The effective length and the possibility of modeling only limited sections of the embankment are discussed. The effects of the embankment height and the longitudinal slope are also addressed. Results point out that the longitudinal slope produces local vibrations that affect the embankment behaviour for excitations close to the fundamental frequencies. The embankment height is the parameter that mainly affects the system dynamics by changing both impedance and kinematic response functions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85361 Collegamento a IRIS

2011
Seismic soil-structure interaction in multi-span bridges: application to a railway bridge
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
Autore/i: Carbonari, Sandro; Dezi, F.; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The effects of SSI on the seismic response of multi-span bridges are investigated by means of a modeling strategy based on the domain decomposition technique. Firstly, the analysis methodology 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 seismic response of the superstructure is evaluated in the time domain by means of user-friendly finite element programs introducing suitable Lumped Parameter Models to take into account the frequency-dependent impedances of the soil-foundation system. Secondly, a real multi-span railway bridge longitudinally restrained at one abutment is analyzed. The input motion is represented by two sets of real accelerograms: one consistent with the Italian seismic code and the other constituted by five records characterized by different frequency contents. The seismic response of the compliant-base model is compared with that obtained from a fixed-base model. Pile stress resultants due to kinematic and inertial interactions are also evaluated. The application demonstrates the importance of performing a comprehensive analysis of the soil-foundation-structure system in the design process, in order to capture the effects of SSI in each structural element that may be beneficial or detrimental.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85161 Collegamento a IRIS

2011
2D higher order model for the dynamic analysis of bridge embankments
PROCEEDINGS OF THE 8TH INTERNATIONAL CONFERENCE ON STRUCTURAL DYNAMICS, EURODYN 2011
Autore/i: Dezi, F.; Morici, M.; Carbonari, Sandro; 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: This work presents a new model for the linear dynamic analysis of bridge embankments which are symmetrical with respect to a longitudinal vertical plane. The embankment kinematics is described by using overall displacements of points lying on the symmetry plane. A higher order approach allows approximating the displacement field of the solid embankment. The problem is formulated in the frequency domain and the equilibrium equations are derived in weak from by means of the Lagrange D’Alembert principle. The solution is achieved numerically with a displacement based finite element approach. The model permits obtaining straightforwardly the dynamic impedances and the kinematic response functions of the embankment that, according to a substructure approach, may be used for the soil-structure interaction analysis of bridges. The model validation is carried out by means of numerical convergence analyses and by comparing results, in terms of dynamic impedances and kinematic response functions, with those obtained by means of 3D finite element models.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85347 Collegamento a IRIS

2011
Linear soil-structure interaction of coupled wall-frame structures on pile foundations
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Carbonari, Sandro; Dezi, F.; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The effects of soil-structure interaction on the response of coupled wall-frame structures on pile foundations subjected to moderate earthquakes are investigated in this paper. A linear finite element procedure for a complete dynamic interaction analysis is developed in the frequency domain accounting for soil-pile interaction and radiation damping. The procedure allows accounting for the actual deformability of the soil-foundation system and modification of the input motion due to the embedded foundation. The free-field motion is obtained by means of a local response analysis which accounts for site amplification. The procedure is adopted to study the effects of compliant pile foundations on the seismic damageability of a coupled wall-frame system. Three different soil profiles are considered and real accelerograms are used as input motions. The calculated results, expressed in terms of the response parameters most significant for the description of damage (such as displacements, inter-storey drifts, accelerations and stress resultants), are compared with those obtained from a conventional fixed base model. Applications demonstrate that performing complete soil-structure interaction analyses may be crucial for the correct evaluation of the behaviour of such systems.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85162 Collegamento a IRIS

2010
Static equivalent method for the kinematic interaction analysis of single piles
Proceedings of the 14th European Conference on Earthquake Engineering, 14ECEE
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: MAEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents a static equivalent approach to estimate the maximum kinematic interaction effects on piles subjected to lateral seismic excitation. Closed-form expressions are reported for the evaluation of maximum freefield soil movements and for the computation of maximum pile displacements. The maximum free-field response is evaluated by means of a modal analysis combined with a suitable damped response spectrum. The pile is schematised as a Winkler’s beam subjected to equivalent static forces defined according to soil vibration modal shapes and amplitudes. Response spectra suggested by national standards or obtained from accelerograms may be used. The procedure may be implemented in simple spreadsheets. Method accuracy is demonstrated by comparing results with those obtained with a more rigorous model. Good results achieved by considering only the first soil vibration mode make the procedure straightforward for practical design purposes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85349 Collegamento a IRIS

2010
Seismic response of a coupled wall-frame structure considering soil-pile-structure interaction
Proceedings of the 14th European Conf. on Earthquake Engineering, 14ECEE
Autore/i: F., Dezi; Carbonari, Sandro; Gara, Fabrizio; G., Leoni
Editore: MAEE
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/48463 Collegamento a IRIS

2010
Static equivalent method for the kinematic interaction analysis of single piles
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: This paper presents a static equivalent approach to estimate the maximum kinematic interaction effects on piles subjected to lateral seismic excitation. Closed-form expressions are reported for the evaluation of the maximum free-field soil movements and for the computation of maximum pile shear force and bending moments. Firstly, modal analysis, combined with a suitable damped response spectrum, is used to evaluate the maximum free-field response. Secondly, the pile is schematised as a Winkler’s beam subjected to equivalent static forces defined according to soil vibration modal shapes and amplitude. The method may be applied by using response spectra suggested by National Standards or those obtained with accelerograms. The procedure proposed may be conveniently implemented in simple spreadsheets or in commercial finite element programs and easily used by practicing engineers. Method accuracy is demonstrated by comparing the results with those obtained with a more rigorous model. Good results may be achieved by considering only the first soil vibration mode making the procedure straightforward for practical design purposes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85160 Collegamento a IRIS

2010
Kinematic bending moments in pile foundations
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: In this paper the kinematic seismic interaction of single piles embedded in soil deposits is evaluated by focusing the attention on the bending moments induced by the transient motion. The analysis is performed by modeling the pile like an Euler-Bernoulli beam embedded in a layered Winkler-type medium. The excitation motion is obtained by means of a one-D propagation analysis. A comprehensive parametric analysis is carried out by varying the main parameters governing the dynamic response of piles like the soil properties, the bedrock location, the diameter and embedment in the bedrock of piles. On the basis of the parametric analysis, a new design formula for predicting the kinematic bending moments for both the cross sections at the deposit-bedrock interface and at the pile head is proposed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85159 Collegamento a IRIS

2009
Soil-pile-structure interaction in the seismic response of coupled wall-frame structures
Atti del XIII Convegno ANIDIS - Bologna, Italy
Autore/i: Carbonari, Sandro; Dezi, F.; Gara, Fabrizio; Leoni, G.
Editore: IMREADY
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: ABSTRACT The aim of this paper is to study the effects of soil-structure interaction on the seismic response of coupled wall-frame structures on pile foundations considering the non-linear behaviour of the superstructure. According to the substructure method, the kinematic interaction analysis is performed by means of a numerical procedure obtaining the dynamic impedance functions and the foundation input motion both necessary to perform inertial interaction analysis. A suitable lumped parameter model is defined to reproduce in the time domain the frequency-dependent impedances of the soil-foundation system. The vertical, horizontal and rotational components of the soil-foundation impedance functions, as well as the roto-translational coupling one, are taken into account. The non-linear inertial interaction analysis is performed by using a finite element model of the superstructure. With reference to a 6-storey 4-bay wall-frame structure, designed according to the Displacement-Based Design and founded on a soft soil deposit, comparisons are made between the compliance base and the fixed base models. The effects of the soil-structure interaction, in terms of structural displacements, base shear, ductility demand and evolution of dissipative mechanisms, are evaluated.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63581 Collegamento a IRIS

2009
Seismic response of structures on pile foundations
Autore/i: Carbonari, Sandro
Editore: Università Politecnica delle Marche
Classificazione: 8 Tesi di dottorato
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/242284 Collegamento a IRIS

2009
Dynamic analysis of pile foundations in layered soils
Proceedings of the Symposium on Progress in Structural Stability and Dynamics & IStructE Asia-Pacific Forum, IJSSD
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: The Hong Kong Institute of Steel Construction
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a numerical model for the analysis of the soil-structure kinematic interaction of single piles and pile groups embedded in layered soil deposits during seismic actions. A finite element model is considered for the pile group and the soil is assumed to be a Winkler-type medium. The pile-soil-pile interaction and the radiation problem are accounted for by means of elastodynamic Green’s functions. 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. The proposed model allows calculating the internal forces induced by soil-pile and pile-to-pile interactions. Comparisons with data available in literature are made to study the convergence and validate the model.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85350 Collegamento a IRIS

2009
Dynamic response of bridges with soil-pile-structure interaction
Atti del XIII Convegno ANIDIS
Autore/i: Carbonari, Sandro; Dezi, F.; Leoni, G.
Editore: IMREADY
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper is aimed at providing a contribution for a more accurate and effective design of bridges founded on piles. A numerical model is employed herein to determine the stresses and displacements in the piles taking into account soil-foundation-structure interaction. A 3D finite element approach is developed for piles and superstructure whereas the soil is assumed to be a Winkler-type medium. The method is applied to single piers representative for a class of bridges. Varying the soil layers characteristics and the pile spacing (from 3 to 5 diameters), bending and axial stresses along piles as well as the pier base shear are computed. A comparison with respect to a fixed-base model is provided. Special issues such as the contribution of the soil profile, of the local amplification and of the rocking at the foundation level are discussed. Soil-structure interaction is found to be essential for effective design of bridges especially for squat piers and soft soil.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85364 Collegamento a IRIS

2009
Kinematic interaction in pile foundations
Atti del XIII Convegno ANIDIS
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: IMREADY
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper the seismic behaviour of single piles embedded in layered soil deposits is evaluated by considering the soil-pile kinematic interaction. The kinematic analysis is performed by using a finite element model for the pile foundation and a Winkler-type medium for the soil. The excitation motion is obtained by means of a 1D propagation analysis of an artificial accelerogram from the bedrock. The analytical model permits calculating the internal forces induced by soil-pile interaction. A comprehensive parametric analysis is carry out by varying the main parameters governing the dynamic response of piles. The influence of the layered soil properties, the bedrock location, the diameter and the bedrock embedment of piles is discussed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85365 Collegamento a IRIS

2009
Static equivalent method for the kinematic interaction analysis of pile foundations
Atti del XIII Convegno ANIDIS
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: IMREADY
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This work presents a simplified procedure for the evaluation of the kinematic stress resultants in single piles subjected to earthquake soil displacements. The procedure is applicable to single piles embedded in homogeneous as well as horizontally layered soil profiles overlaying a rigid formation. By neglecting radiation damping the evaluation of the effects induced in the piles by the propagation of seismic waves in the soil is studied by means of a static equivalent procedure, without the use of dynamic analyses. Piles are modelled as elastic beams on Winkler restraints and are pushed by the earthquake soil displacements provided by a response spectrum analysis of the soil profile. The soil is assumed to be homogeneous with constant shear modulus and density and to behave elastically. A validation of the method is carried out comparing results with those furnished by more sophisticated dynamic soil-pile interaction analyses.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85363 Collegamento a IRIS

2009
A model for the 3D kinematic interaction analysis of pile groups in layered soils
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Classificazione: 1 Contributo su Rivista
Abstract: The paper presents a numerical model for the analysis of the soil–structure kinematic interaction of single piles and pile groups embedded in layered soil deposits during seismic actions. A finite element model is considered for the pile group and the soil is assumed to be a Winkler-type medium. The pile–soil–pile interaction and the radiation problem are accounted for by means of elastodynamic Green’s functions. 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. The model proposed allows calculating the internal forces induced by soil–pile and pile-to-pile interactions. Comparisons with data available in literature are made to study the convergence and validate the model. An application to a realistic pile foundation is given to demonstrate the potential of the model to catch the dynamic behaviour of the soil–foundation system and the stress resultants in each pile.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85158 Collegamento a IRIS

2008
Effects of soil-pile-structure interaction on the non-linear seismic response of coupled wall-frame systems
Proceedings of the 14th World Conference on Earthquake Engineering, WCEE 2008
Autore/i: Carbonari, Sandro; Dezi, F.; Gara, Fabrizio; Leoni, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: ABSTRACT The aim of this paper is to study the effects of Soil-Structure Interaction (SSI) on the seismic responseof coupledwall-frame structures on pile foundations considering the non-linear behaviour of the superstructure. According to the substructure method, the kinematic interaction analysis is performed by means of a numerical procedure obtaining the dynamic impedance functions and the foundation input motion both necessary to perform inertialinteraction analysis. A suitable Lumped Parameter Model (LPM) is defined to reproduce in the time domain the frequency-dependent impedances. The vertical, horizontal and rotational components of the soil-foundation impedance functions, as well as the roto-translational coupling one, are taken into account. The non-linearinertial interaction analysis is performed by using a finite element model of the superstructure. With reference to a 6-storey 4-bay wall-frame structure, designed according to the Displacement-Based Design and founded on a soft soil deposit, comparisons are made between the compliance base and the fixed base models. The effects of the soil-structure interaction, in terms of structural displacements, base shear, ductility demand and evolution of dissipative mechanisms, are evaluated.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/47717 Collegamento a IRIS

2008
Static equivalent method for the kinematic interaction analysis of pile foundations
Proceedings of the 14th World Conference on Earthquake Engineering, 14WCEE
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This work presents a simplified procedure for the evaluation of the kinematic stress resultants in single piles subjected to earthquake soil displacements. The procedure is applicable to single piles embedded in homogeneous as well as horizontally layered soil profiles overlaying a rigid formation. By neglecting radiation damping the evaluation of the effects induced in the piles by the propagation of seismic waves in the soil is studied by means of a static equivalent procedure, without the use of dynamic analyses. Piles are modelled as elastic beams on Winkler restraints and are pushed by the earthquake soil displacements provided by a response spectrum analysis of the soil profile oscillating. The soil is assumed to be homogeneous with constant shear modulus and density and to behave elastically. A validation of the method is carried out comparing results with those furnished by more sophisticated dynamic soil-pile interaction analyses.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85352 Collegamento a IRIS

2008
Kinematic interaction in pile foundations
Proceedings of the 14th World Conference on Earthquake Engineering, 14WCEE
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: In this paper the seismic behaviour of single piles embedded in layered soil deposits is evaluated by considering the soil-pile kinematic interaction. The kinematic analysis is performed by using a finite element model for the pile foundation and a Winkler-type medium for the soil. The excitation motion is obtained by means of a one-D propagation analysis of an artificial accelerogram from the bedrock. The analytical model permits calculating the internal forces induced by soil-pile interaction. A comprehensive parametric analysis is carry out by varying the main parameters governing the dynamic response of piles. The influence of the layered soil properties, the bedrock location, the diameter and the bedrock embedment of piles is discussed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85351 Collegamento a IRIS

2008
Soil-structure interaction in the seismic response of coupled wall-frame structures on pile foundations
Proceedings of the Seismic engineering international conference commemorating the 1908 Messina and Reggio Calabria Earthquake, MERCEA’08
Autore/i: Carbonari, Sandro; Dezi, F.; Leoni, G.
Editore: AMER INST PHYSICS, 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents a study on the seismic response of coupled wall-frame structures founded on piles. A complete soil-structure interaction analysis is carried out with reference to a case study. Three different soils and seven real accelerograms are considered. Local site response analyses are performed in order to evaluate the incoming free-field motion at different depths and the ground motion amplifications. A numerical model, accounting for the pile-soil-pile interaction and for material and radiation damping, is used to evaluate the impedance matrix and the foundation input motion. The domain decomposition technique is adopted to perform time-domain seismic analyses introducing Lumped Parameter Models to take into account the impedance of the soil-structure system. Applications show that the rocking phenomena affect the behaviour of the structure by changing the base shear distribution within the wall and the frame and by increasing the structural displacements.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85354 Collegamento a IRIS

2008
Kinematic interaction and rocking effects on the seismic response of viaducts on pile foundations
2008 SEISMIC ENGINEERING CONFERENCE COMMEMORATING THE 1908 MESSINA AND REGGIO CALABRIA EARTHQUAKE, PTS 1 AND 2
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: AMER INST PHYSICS, 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper is aimed at providing a contribution for a more accurate and effective design of bridges founded on piles. A numerical model is employed herein to determine the stresses and displacements in the piles taking into account soil-foundation-structure interaction. A 3D finite element approach is developed for piles and superstructure whereas the soil is assumed to be a Winkler-type medium. The method is applied to single piers representative for a class of bridges. Varying the soil layers characteristics and the pile spacing (from 3 to 5 diameters), bending and axial stresses along piles as well as the pier base shear are computed. A comparison with respect to a fixed-base model is provided. Special issues such as the contribution of the soil profile, of the local amplification and of the rocking at the foundation level are discussed. Soil-structure interaction is found to be essential for effective design of bridges especially for squat piers and soft soil.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85353 Collegamento a IRIS

2008
Seismic response of coupled wall-frame structures on pile foundations
TAILOR MADE CONCRETE STRUCTURES: NEW SOLUTIONS FOR OUR SOCIETY
Autore/i: Carbonari, Sandro; Dezi, F.; Leoni, G.
Editore: CRC PRESS-TAYLOR & FRANCIS GROUP, 6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: A study on the seismic behaviour of coupled wall-frame structures founded on piles is presented. Three different foundation soils are considered and the seismic excitation at the outcropping bedrock is represented using 7 real accelerograms. Local site response analyses are performed to evaluate the incoming free-field motions. A numerical model, accounting for pile-soil-pile interaction and for material and radiation damping, is used to evaluate the impedance matrix and the foundation input motion. Dynamic analyses are then performed in the time domain by considering fixed (FBMs) and compliance-base models (SSIMs). Applications show that the effects associated to the rocking behaviour of the wall sensibly affect the dynamic response of the system increasing the structural displacements and producing a change in the distribution of the seismic demand within the wall and the frame.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85356 Collegamento a IRIS

2008
Seismic response of bridges on pile foundations considering soil-structure interaction
TAILOR MADE CONCRETE STRUCTURES: NEW SOLUTIONS FOR OUR SOCIETY
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: CRC PRESS-TAYLOR & FRANCIS GROUP, 6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper attempts to assess the influence of dynamic soil-structure interaction on the behaviour of bridges founded on rigidly capped floating vertical pile groups. A numerical model for the analysis of the soil-structure interaction of generic structures on pile foundations is presented based on a finite element approach for superstructure and pile group whereas the soil is assumed to be a Winkler-type medium. The method is applied to single piers representative for a class of bridges. Varying the soil condition and the foundation geometry, same comparisons are made with respect to the fixed base model. Special issues such as the contribution of the soil profile, of the local amplification and of the rocking at the foundation level are dis-cussed. Soil-structure interaction is found to be essential for effective design of bridges especially for squat piers and soft soil.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85355 Collegamento a IRIS

2008
Effects of soil-structure interaction on the seismic damageability of coupled wall-frame systems on pile foundations
LIFE-CYCLE CIVIL ENGINEERING
Autore/i: Dezi, F.; Carbonari, Sandro; Leoni, G.
Editore: CRC PRESS-TAYLOR & FRANCIS GROUP, 6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: The paper presents a study on the seismic damageability of coupled wall-frame structures founded on piles. A complete soil-structure interaction analysis is carried out with reference to a case study. Three different soils and seven real accelerograms are considered. Local site response analyses are performed in order to evaluate the incoming free-field motion at different depths and the ground motion amplifications. A numerical model, accounting for the pile-soil-pile interaction and for material and radiation damping, is used to evaluate the impedance matrix and the foundation input motion. Dynamic analyses are then performed in the time domain by considering fixed and deformable base models. In the second case, the effects of the soil-foundation system deformability are taken into account with Lumped Parameter Models calibrated on the impedance functions previously evaluated. Rocking phenomena affect the behaviour of the structure by increasing the interstorey drifts. Evaluation of the return period of damaging events shows how for soft soils the usual design procedure may be not effective in protecting the building against seismic damages.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85357 Collegamento a IRIS

2007
Steel-concrete composite frame equipped with high damping rubber devices and buckling restrained braces: experimental results
Atti del XXI Congresso C.T.A.
Autore/i: Carbonari, Sandro; Dall’Asta, A.; Dezi, Luigino; Leoni, G.; Ragni, Laura; Zito, L. F.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/72366 Collegamento a IRIS

2007
Impedances of pile foundations for the spatial dynamic response of structures
Proceedings of the 3rd International Conference on Structural Engineering, Mechanics and Computation, SEMC 2007
Autore/i: Carbonari, Sandro; Dall’Asta, A.; Dezi, F.; Leoni, G.
Editore: Millpress
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents a numerical model, based on the domain decomposition technique, for the analysis of the kinematic interaction of pile groups and for the evaluation of the foundation impedances and the foundation input motion which may be used in studying generic spatial superstructures. A finite element model is considered for the pile group and the soil is assumed to be a Winkler-type medium. The soil-pile interaction is included by considering dynamic impedances according to simplified available theories. Comparisons with data available in the literature show the potential of the model in catching both the static and dynamic behaviour of the foundation: at zero frequency the model can provide the static group efficiency factors; at high frequencies, for large pile spacing-diameter ratio, typical interference phenomena are caught.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85359 Collegamento a IRIS

2007
Dynamic spatial response of structures considering soil-foundation-structure interaction: analytical model
Atti del XII Convegno ANIDIS
Autore/i: Dezi, F.; Carbonari, Sandro; Dall’Asta, A.; Leoni, G.
Editore: Plus
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: This paper presents a numerical model, based on the domain decomposition technique, for the analysis of the soil-structure kinematic and inertial interaction of generic structures on pile foundations. A finite element model is considered for the pile group and the soil is assumed to be a Winkler-type medium. The soil-pile in-teraction is included by considering dynamic impedances according to simplified available theories. The iner-tial interaction between foundation and superstructure is also captured by a finite element approach. The static condensation of the problem leads to the definition of the equivalent model in which the foundation is re-placed by deformable restraints. Some comparisons with data available in the literature show the potential of the model in catching both the static and dynamic behaviour of the foundation.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/85368 Collegamento a IRIS

2007
Shear deformable steel-concrete composite beam model
Atti del XXI Congresso C.T.A.
Autore/i: Carbonari, Sandro; Dezi, Luigino; Gara, Fabrizio; Leoni, G.
Editore: Dario Flaccovio Editore
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Atti del XXI Congresso C.T.A. - Catania, Italy
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/63584 Collegamento a IRIS

2007
Application of HDR devices for the seismic protection of steel-concrete composite frames: experimental results
Proceedings of the 6th Int. Conf. on Steel and Aluminium Structures
Autore/i: Dall'Asta, A.; Leoni, G.; Carbonari, S.; Dezi, L.; Ragni, L.; Zito, L.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/52307 Collegamento a IRIS

2007
Load-consistent effective width for the analysis of composite steel-concrete bridge decks
5th International Conference on Advances in Steel Structures, ICASS 2007; Singapore; Singapore; 5 December 2007 through 7 December 2007; Code 88969
Autore/i: Carbonari, Sandro; Dezi, Luigino; Gara, Fabrizio; G., Leoni
Editore: Research Publishing Services, Singapore
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Abstract: Abstract This paper proposes new effective widths for the analysis of twin-girder steel-concrete composite bridge decks. The method permits evaluating the normal longitudinal stress on the slab by means of a cross sectional analysis starting from the results of the structural analysis performed by considering the nominal width of the slab. The effects of a single load layout, support settlements and concrete shrinkage, as well as the maximum effects obtained by considering the envelopes of bending moments, for example due to traffic load, can be caught. Comparisons with other methods performed on realistic continuous twin-girder composite bridge decks demonstrate the simplicity and effectiveness of the method proposed.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/53536 Collegamento a IRIS

2007
Application of HDR devices for the seismic protection of steel-concrete composite frames: experimental results
5th International Conference on Advances in Steel Structures, ICASS 2007; Singapore; Singapore; 5 December 2007 through 7 December 2007; Code 88969
Autore/i: Dall'Asta, A.; Leoni, G.; Carbonari, Sandro; Dezi, Luigino; Ragni, Laura; Zito, L.
Classificazione: 4 Contributo in Atti di Convegno (Proceeding)
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/58501 Collegamento a IRIS




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