RELIABILITY ANALYSIS OF FOUNDATION STRUCTURE INTERACTION

Abstract

The influence of site effects and soil-structure interaction effects on the reliability of linear structures supported on the surface of a linear viscoelastic soil layer is investigated. The base shear and the total displacement of a short and squatty building as well as a tall and slender building due to earthquake excitations are determined using input power spectral densities for three different soil conditions, viz. soft soil, medium soil and firm soil. Reliability evaluation for the structural response is performed using stationary analysis with the assumption that crossings of the threshold are sufficiently rare as to constitute a Poisson process. Based on the concepts of Yang's nonstationary envelopes and first-passage reliability estimates via extreme point process, nonstationary evolutionary random vibration analysis is applied to obtain the response reliability for the critical case. The present study shows that soil-structure interaction considering site effects may reduce the reliability of the base shear as well as the total displacement.