when structures are subjected to strong ground motion excitations, structural elements may be prone to yielding, and consequently experience significant levels of inelastic behavior. the effects of inelastic behavior on the distribution of peak floor loads are not explicitly accounted for in current seismic code procedures. during recent years, many studies have been conducted to develop new de...

The incident angle of ground motion is one of the sources of uncertainty in the seismic response of buildings. Moreover, understanding the structural response to the impose ground motion may cause significant changes in the maximum response of buildings. In order to investigate the effect of the spatial distribution of orthogonal components of earthquake strong motion on the structural response...

worldwide networks of seismic recording instruments mostly record only translational ground motion in two or three orthogonal directions. rotational component of earthquake is not commonly recorded. several theories are available to estimate a torsional component from recorded translational components of ground motion. in this paper detailed investigations are made to study the relative perform...

Dynamic Ratcheting (DR) is a nonlinear dynamic phenomenon occurring in hysteretic damping systems. It means the structural plastic deformation increases asymmetrically in successive cycles under an earthquake excitation. Although it is generally recognized that DR is closely related to the frequency contents of an earthquake excitation applied to thestructure, no targeted analysis has bee...

Understanding strong ground motions in the near-fault areas is important for seismic risk assessment in densely populated areas. In the past, lack of information on strong ground motion for large and moderate earthquakes led to the use of mainly far field large and moderate earthquake records in equations for calculation of the strong ground motion parameters. In this article, we collected and ...

A set of time-synchronized strong-motion accelerograms, obtained on the San Juan Bautista 156/101 Separation Bridge in California during the 6 August 1979 Coyote Lake earthquake (ML = 5.9), are used to study the spatial variation of ground motion at the bridge site, including traveling wave effects and the influence of multiple-support excitation. Analysis of the ground motion recorded at the b...

according to performance-based seismic design method by using energy concept, in this paper it is tried to investigate the duration and damping effects on elastic input energy due to strong ground motions. based on reliable iranian earthquake records in four types of soils, structures were analyzed and equivalent velocity spectra were computed by using input energy. these spectra were normalize...

during the past decades, attempts have been made to develop an early warning system for coming destructive earthquakes a few seconds before the ongoing ground motion. in this paper, a practical method for the early warning of earthquakes in south iran is presented. this region is selected for study because it has high potential for generating earthquakes and has a more complete strong ground mo...

Most instruments used in seismological practice to record ground motion are pendulum seismographs, velocigraphs, or accelerographs. In most cases it is assumed that seismic instruments are only sensitive to the translational motion of the instrument’s base. In this study the full equation of pendulum motion, including the inputs of rotations and tilts, is considered. It is shown that tilting th...