Site response analysis based on fundamental period of shallow soil structure

Abstract

There are many factors that affect site response hit with an earthquake. Some significant factors include the key traits of a shallow shear wave velocity structure which include traits like its fundamental period and average shear wave velocity. Some key site responses that people are highly interested are the amplification of a seismic ground motion in different types of soil profile and its period elongation.

It is observed that the intensity of ground motions due to Sumatran earthquake in places in Singapore like Kallang and Bukit Timah are different. This project is interested to investigate the reasons behind the behaviors of different soil site and to study the key relation and pattern of site responses.

Experiment will be carried out using a computer program that will simulate different responses of specific soil profile subjected to different earthquake intensities. Correlation between spectral amplification and its fundamental period will be observed. Since several models can possibly represent a certain fundamental period and spectral amplification also depends on the characteristics of the bedrock motion, statistical analysis will be conducted to obtain representative amplification spectra that correspond to a particular fundamental period.

Amplifications for certain characteristics of shallow soil structure will be simulated using EERA which assumes equivalent linear model. EERA, which is the main computer program used in this project, stands for Equivalent-linear Earthquake site Response Analysis. It is a program by J.P Bardet, K.Ichii, and C.H.Lin and it assumes simplified soil deposit conditions such as horizontal soil layers of infinite extent.