Liquefaction assessment using alternative approaches: a case study of Ho Chi Minh City stratigraphy

Liquefaction has been known as a phenomenon in which the shear strength and stiffness of saturated soil are reduced by the generation of pore water pressure under earthquake loading. Consequently, liquefaction-induced settlement can result in severe damage including building cracks or slope failure, which pose a threat to human lives and properties. In the current Vietnamese standard TCVN 9386:2012, liquefaction potential hazard is often evaluated using the simplified method, which solely identifies the areas with a high risk of liquefaction. Prediction of Safety Factor (FS), Settlement (S), Liquefaction Potential Index (LPI), and Liquefaction Severity Number (LSN) has not received sufficient attention to a completeness standard. This study assesses the liquefaction of the site at Ho Chi Minh City, Vietnam by using four conventional methods: the simplified procedure, linear equivalent analysis, loosely-coupled effective stress analysis, and fully-coupled effective stress analysis based on standard penetration test (SPT) data in Ho Chi Minh Metropolitan City. A class of seismic events that are compatible with the design response spectrum in the Vietnamese standard TCVN 9386:2012 is used as input ground motion at the bedrock. According to the results of different methods, maps of ground settlement, LPI, and LSN are proposed as useful references for construction works on such soils, which may have a high potential for liquefaction and subsidence.