Establising the empirical relation between Microtremor and Soil Liquefaction :Case Study in Tainan Urban Area

Abstract

In this study we used microtremor which is convenient and non-destructive to acquire the site characteristics and analyzed it by Nakamura method(1989) which also called HVSR Finally establishing the empirical relation between microtremor and soil liquefaction in Tainan urban area There are two parts in this study In first part we will use GIS software to plot the distribution of predominant frequencies and compare it with borehole data past geologic research and soil liquefaction regions of 0206 Meinong earthquake in Tainan urban area In the second part we will use ANN tool to help us connect site characteristics which got from HVSR with liquefied potential which got from SPT borehole data by HBF method (2005) We used the site characteristics as inputs on the other hand liquefied potential as targets With different model assumptions finally picked up the model that has highest success rate From the result of first part microtremor exactly can reflect the geology of Tainan urban area And focus on these liquefied regions in 0206 earthquake most of these regions has predominant frequency that below 1 35Hz which are relative weak places From the result of second part the best ANN model has success rate round 74% in predicting one place is liquefied or non-liquefied it’s helpful for preliminary classification However if we want to predict one place is low medium or high liquefied potential the success rate will drop Finally we can conclude that microtremor will really show the characteristics of one place And it’s helpful for predicting soil liquefaction in one place

Date of Award	2019
Original language	English
Supervisor	Jian-Hong Wu (Supervisor)