Using a Stochastic Model to Study the Ground Motion of Comprehensive Subsurface Structure

Abstract

The seismic response analysis of buildings and bridges use earthquake acceleration time histories as input data. But there is always a lack of earthquake time histories in regions where buildings are constructed, which makes ground motion simulation is one of the most important problems in civil engineering domain. In this study, the strong motion stations of boring log data collected within Lanyang plain have been combined with the subsurface layers of Lanyang plain obtained by using geophysical method to construct a comprehensive subsurface structure of Lanyang plain. Available papers and reports on nonlinear dynamic soil characteristics have been reviewed to determine appropriate soil parameters for representing soils in Lanynag plain. In this research, the stochastic seismic model developed by Boore (1983, 2005) will be used to simulate a set of rock-outcrop synthetic acceleration time histories. The acceleration time histories at the rock-outcrop from this study will be compared with the real earthquake record for all the soil sites, the acceleration time histories at the ground surface will be generated from nonlinear site response analyses using the computer program SHAKE91. For the strong motion station, we compare the earthquake spectrum and real earthquake spectrum to investigate the appropriateness in the Ilan area. These ground motions may be used in the field of disaster reduction, such as the calculation of the ground response subject to earthquakes using the SHAKE computer program or the evaluation of the safety of buildings and bridges.