Hossein Tahghighi

University of Kashan · Civil Engineering

The study of past earthquakes indicates that permanent landform variations are the main cause of tunnels failure in comparison with seismic vibrations. In this study, the effect of reverse fault displacements on tunnels has been investigated using 2D and 3D FEM. An explicit dynamic analysis method has been used to take the effect of fault movement...

This paper investigates the influence of isolation systems on the seismic behavior of urban reinforce concrete bridge. The performance of the Hesarak Bridge constructed in Karaj city, Iran with two isolation systems; i.e. the existing elastomeric rubber bearing (ERB) and a proposed lead rubber bearing (LRB) is discussed. The numerical model was imp...

This study aimed to investigate whether the seismic performance and vulnerability of reinforced concrete (RC) structures were affected by soil-structure interaction (SSI). A set of RC frames located on three soil types were designed and modeled using the OpenSees finite-element framework. A nonlinear Winkler-based method was applied to model the so...

Buckling-restrained brace (BRB) is a specific kind of bracing system which has an acceptable energy dissipation behavior in a way that would not be buckled in compression forces. However, considerable residual deformations are noticed in strong ground motions as a result of the low post-yield stiffness of the BRBs. The seismic performance of a mode...

Heritage structures are an important part of the history of each community as well as an economic resource. This study aims to investigate the earthquake damage and failure mechanism of a historic Bazaar located in Kashan (center of Iran), which dates back to the eighteenth century. Numerical models were built by a macro method, considering two cas...

Bucking restrained braced frame (BRBF) is a special type of concentrically braced frames that the braces do not buckle in compression and as a result shows a desirable energy dissipation behavior. However, low post-yield stiffness of these braces causes large residual deformations at high levels of earthquake itensities. The aim of this article is...

The importance of earthquake effects on the storage reservoir forces researchers to investigate the seismic response of reservoirs. Despite recent advances in design standards, there is no acceptable method for time-history analysis for such structures, with high structural stiffness. The seismic codes such as Standard No. 2800 and ASCE/SEI 7 for c...

Heritage structures are an important part of the history of each society as well as an economic source. Accordingly, the protection and maintenance of these structures have cultural, economic and social significance. Today, the decision of the responsible organizations and the recommendation of the international reference councils for the monuments...

The significance of earthquake effects on storage tanks compels researchers to investigate tanks seismic responses. In spite of the recent design codes developments, there is no accepted procedure to scale ground motions to perform time-history analysis for these very stiff structures. Nevertheless, standards for conventional structures have long b...

For the structure resting on a flexible medium, the dynamic response of the structure will be different from the fixed-base condition owing to the interaction between the soil and the structure. Nevertheless, the common practice in seismic performance assessment assumes that structures are fixed to their base, which maybe a realistic hypothesis onl...

Historical heritage structures are especially vulnerable to earthquakes because they were designed only for gravity loads without any consideration of lateral loads. For this reason, the preservation and maintenance of these structures are of great cultural, economic, and social importance. The present study investigates the seismic vulnerability o...

Kashan is one of the earthquake-prone cities of IRAN. Thus, due to the presence of numerous historical and cultural structures in Kashan, vulnerability assessments and retrofitting activities is inevitable in most cases. This paper presents the results of vulnerability assessment of the historical bazar located in Kashan. The geometry of the most c...

Confinement of both existing and newly constructed reinforced concrete (RC) frames by fibre reinforced polymer (FRP) has been commonly used in recent decades. This is because of its ability to enhance the behavior of RC frames under lateral loading.The purpose of this research is to perform a numerical study on effect of FRP confinement on strength...

Seismic loads can cause severe damages to bridge, and lead to malfunction of transportation networks. Dissimilar to the static behaviour, the dynamic response of bridges depends on several structural parameters such as material properties, damping and mode shapes. Furthermore, earthquakes characteristics can significantly change the structural resp...

Performance-based earthquake engineering requires accurate estimation of the seismic demand and the capacity of structures. In recent years, various kinds of nonlinear static and dynamic analyses have been developed for seismic evaluation of structures. Nonlinear dynamic time history analysis method not only is very time consuming, but also proper...

Recent studies have shown that the e�ects of Soil-Structure Interaction (SSI) may be detrimental to the seismic response of structure, and the neglect of SSI in analysis may lead to an un-conservative design. The objective of this study is to simulate the performance of multi-storey building-foundation systems through a Winklerbased approach. Four...

Response evaluation of buried steel pipelines at intersection with active faults is among the top seismic design priorities. This is because the axial and bending strains induced to the pipeline by step-like permanent ground deformation may become fairly large and lead to rupture, either due to tension or due to buckling. Surface faulting has accou...

Recent studies have shown that the effects of Soil-Structure Interaction (SSI) may be detrimental to the seismic response of structure, and the neglect of SSI in analysis may lead to an un-conservative design. The objective of this study is to simulate the performance of multi-storey building-foundation systems through a Winklerbased approach. Four...

A nonlinear p–y element was provided which can simply model the behavior of a pile group foundation subjected to lateral loading. Its elasto-plastic side soil is expressed as a Winkler-type distributed model. Despite the simplification involved in modeling such a complex phenomenon the proposed nonlinear soil model can reproduce the system behavior...

This paper is going to assess the progressive collapse behavior of seismically code designed steel frame buildings. The structural systems considered are concentrically braced frame (CBF) and moment resisting frame (MRF). The progressive collapse design guidelines typically recommend simplified analysis procedures involving instantaneous removal of...

Pipelines are often referred as "lifelines" and this demonstrates that pipelines play an important role in human's life. Based on the damage mechanism of buried pipelines, seismic effects can be either caused by transient strain and curvature in the ground due to traveling wave effects or caused by permanent ground deformations; such as fault defor...

Seismic codes nowadays include design requirements in order to taking Soil-Structure Interaction (SSI) into account for realistic modelling of structures. This study is conducted to assess the behaviour of steel structure-soil systems using Standard No. 2800 and FEMA-440. Steel frame buildings are assumed to have various heights and different later...

Recent seismic codes include design requirements in order to take soil-structure interaction (SSI) into account for realistic modelling of structures. The paper investigates the performance of multi-story building-foundation systems through a Winkler-based approach. A set of 4-, 8-, 12-and 16-story steel moment resisting frame buildings on three so...

Pipelines are often referred to as lifelines, demonstrating that they play an important role in human's life. Based on the damage mechanism, the permanent ground movements of active faults can have the most severe earthquake effects on buried pipelines. In this study, the effects due to strike-slip faulting have been investigated using 3D FEM, Wink...

The aim of this article is to examine the validity of simulating near-fault ground motions using stochastic finite-fault methods. We used the comprehensive database available from the 1999 Chi-Chi earthquake. We simulated accelerograms, peak ground motions, and response spectra from 35 strong motion stations within a distance of about 10 km from th...

On March 11 th 2011, a massive scale earthquake of magnitude 9.0 occurred on off the pacific coast of Tohoku region, Japan named in short as "the 2011 Tohoku earthquake". Large earthquakes can generate far-source long-period ground motions consist primarily of surface waves in distant sedimentary basins with the help of path effects. Large-scale st...

Unique to the near-source region of a large earthquake is the occurrence of strong impulsive ground motion and surface faulting referred to as ‘fling-step’ motion. The objective of this study is to synthesize broad-band time histories over a wide range of frequencies by characterizing rupture directivity and fling effects from the comprehensive str...

The response of laterally loaded pile foundations may be significantly important in the design of structures. The aim of this paper is to derive the dynamic stiffness of grouped piles subjected to lateral loading hinged into a rigid pile cap. For this purpose, a computer program based on Thin Layered Element method is used. The results of the progr...

Unique to the near-source large earthquake is the occurrence of strong impulsive long-period ground motion and surface faulting. The well-recorded time history event of the 1999 Chi-Chi earthquake has confirmed the existence of permanent displacements, referred to as 'fling-step', coupled with rupture directivity motions. The objective of this stud...

The stochastic method for finite fault is applied to simulate near-source ground motions from the 21 September 1999, Mw 7.6 Chi-Chi, Taiwan dip-slip earthquake. We simulated accelerograms, peak ground motions, and response spectra from 35 strong motion stations within a distance of about 10 km from the ruptured fault plane. The simulations are in g...

A nonlinear p–y element was provided which can simply model the behavior of a pile group foundation subjected to lateral loading. Its elasto-plastic side soil is expressed as a Winkler-type distributed model. Despite the simplification involved in modeling such a complex phenomenon the proposed nonlinear soil model can reproduce the system behavior...

The Authors have recently proposed an idea to define the parameters of a logical nonlinear Winkler soil model. In the current paper, the capability of the model will be verified to evaluate the response of grouped piles beneath a superstructure. The results are then compared with those from available physical model data and 3D FE analysis to confir...

A simple numerical model is presented for handling both linear and nonlinear soil-pile interactions. In the present method, the diagonal terms of the exact soil impedance matrix define the elastic characteristics of Winkler side soil springs. When its off-diagonal terms are described as a function of the pile's active length, they were found less d...

The Bam earthquake of December 26, 2003 (Mw6.5) occurred around the city of Bam in southeast Iran. Because the earthquake happened early in the morning at 01: 56: 56 (GMT, 05: 26: 26 local time), most of the reported 43,100 victims were killed in their dwellings. In Iran, there are dense strong ground motion networks for describing the seismologica...