Effect of Incident Seismic Waves on Accidental Eccentricity of Structures

In seismic analysis, assumption of rigid or flexible foundation leads to different results. Moreover, in torsional response, unpredictable factors affect on results. In order to study the effect of seismic waves and flexibility of foundation-structure on the torsional response, an idealized system is consideredwhich includes single storey building with double eccentricity resting on a homogenous elastic half space. Results show that several parameters affect on torsional response: embedment, frequency, mass and flexibility ratios. Regression on results is used to develop an equation which is proposed for evaluation of eccentricity and is able to take these parameters effectively into account