near-fault ground motions have caused very much damage in the vicinity of seismic sources during recent earthquakes. it is well known that under specific circumstances, intensive ground shakings near fault ruptures may be characterized by short-duration impulsive motions. this pulse-type motion is generally particular to the forward direction, where the fault rupture propagates towards the site...

The significance of stochasticity in the characteristics of the surface layers of a site to the resulting spatial variation of seismic ground motions and the seismic ground strains is investigated. For this purpose, an analytical site-specific model is developed. The model approximates the site topography by a horizontally extended layer with random characteristics overlying a half-space (bedro...

Endurance Time Method (ET) is a dynamic analysis in which structures are subjected to intensifying accelerograms that are optimized in a way that seismic performance of structures can be estimated at different hazard levels with the best possible accuracy. For the currently available ET accelerograms, regardless of the shaking characteristic, an excitation level is recognized as a representativ...

amplitudes of seismic waves decrease with distance according to anelastic properties of the earth and geometrical spreading. the attenuation of ground-motion amplitudes in the frequency domain is an important problem in engineering seismology. it is of particular practical interest in the regions such as zagros (iran). the zagros fold- thrust belt, as a part of alpine- himalayan orogenic belt i...

In the present study, ten steel-moment resisting frames (SMRFs) having different numbers of stories ranging from 3 to 20 stories and fundamental periods of vibration ranging from 0.3 to 3.0 second were optimized subjected to a set of earthquake ground motions using the concept of uniform damage distribution along the height of the structures. Based on the step-by-step optimization algorithm dev...

Near-fault ground motions have caused very much damage in the vicinity of seismic sources during recent earthquakes. It is well known that under specific circumstances, intensive ground shakings near fault ruptures may be characterized by short-duration impulsive motions. This pulse-type motion is generally particular to the forward direction, where the fault rupture propagates towards the site...

This paper presents the formulation of a time-dependent seismic fragility format for bridges, as well as new insights into the potential effects of aging and deterioration on seismic vulnerability traditionally neglected in fragility modeling, including joint impacts of multiple component deterioration not investigated to date. The study evaluates the impact of lifetime exposure to chlorides fr...

Ground-motion (attenuation) relations are used to estimate strong ground motion for many engineering and seismological applications. Where strongmotion recordings are abundant, these relations are developed empirically from strong-motion recordings. Where recordings are limited, they are often developed from seismological models using stochastic and theoretical methods. However, there is a larg...