Structural Response to Uncertain Seismic Excitations

Abstract

Probabilistic and statistical descriptors are developed for the response of nonhysteretic oscillators subject to modulated Gaussian ground acceleration with uncertain scale. The probabilistic descriptors correspond to postulated values of the scale of the ground acceleration process while the statistical descriptors account for the uncertainty in this parameter. The analysis focuses on the mean (failure) rate at which the response exceeds the structural strength. It shows that unconservative designs can result when the uncertainty in the scale of the ground acceleration is disregarded. This unfavorable effect is less significant for nonlinear structures than for linear structures in the cases examined in the paper.