A Study of CPT-based Methods for Evaluating Liquefaction-induced Settlements and Lateral Spreads

Abstract

This study mainly uses historical cases of liquefaction in various countries and cone penetration test (CPT) data to establish an empirical model for evaluating liquefaction-induced ground displacement Firstly use the collected cases to discuss the applicability and shortcomings of the current empirical model Next find the relationship between the ground displacement and the predicted displacement and use the root mean square error (RSME) to compare the models and find out the best prediction result Three liquefaction susceptibility assessment indexes are added: Liquefaction Potential Index(LPI) Liquefaction Severity Number(LSN) and Modified Liquefaction Potential Index(LPI*) that takes into account terrain Regression analysis is used and the results show that regardless of the settlements or lateral spreads all have good fitting conditions with LPI* The calculation concept of LPI* is simple and convenient and it can be used as an assessment method of liquefaction-induced displacement In addition changing the integral depth to the height of free face plus 2 meters to evaluate the lateral spread can get great prediction results better than the existing surface deformation models The study also explored the distribution characteristics of the formation parameters of the ground deformation cases The formation parameters use the CPT test parameters In this study the distribution of parameters of the liquefied layer in the settlements cases is cone resistance(qc) 2?4 5 MPa sleeve friction resistance(fs) 20?45 KPa pore water pressure(u2) -50?25 KPa normalized cone resistance(Qtn) 30?60; the distribution of parameters of the liquefied layer in the lateral spreads cases is cone resistance (qc) 2?7 MPa sleeve friction resistance (fs) 10?60 KPa pore water pressure(u2)-20?60 KPa normalized cone resistance(Qtn) 30?90

Date of Award	2020
Original language	English
Supervisor	Der-Her Lee (Supervisor)