A Method for Estimating Bedrock Ground Motion Based on Nonlinear Time-history Analysis

Abstract

This paper proposes a method for estimating earthquake motion at the engineering bedrock level using surface seismic observation records, by employing nonlinear time domain analysis. In addition to general optimization methods, the perturbation waveform incorporated in a forward analysis was used to drastically improve the convergence of calculations. Furthermore, the equivalent single-degree-of-freedom model of the ground was incorporated when performing the nonlinear analysis in the time domain. As a result, the calculation time decreased sufficiently to be able to estimate seismic motion more economically in terms of cost, while still considering complex soil nonlinearity.