Influence of Groundwater Table Fluctuation on Liquefaction Potential Analysis Using Cyclic Stress Approach

Abstract

In addition to earthquakes, groundwater table (GWT) also contributes to uncertainty in liquefaction analysis, so it needs to be considered. This research was conducted by analyzing the liquefaction potential with a cyclic stress approach using standard penetration test data and cone penetration test data with varied GWT in a case study of building design in Sleman, Yogyakarta Special Region. The liquefaction safety factor (FS L ) was calculated to obtain the liquefaction potential index (LPI) and liquefaction severity index (LSI). Based on the survey results, the GWT ranges from -6 m to -8 m. Referring to the FS L , there are several soil layers that have liquefaction potential at all GWT variations. The shallower the GWT, the greater the LPI and LSI values at the same point will be. Changes in GWT from -8 m to -6 m cause changes in the LPI and LSI classifications at several points. Based on LPI classification, the location belongs to high to very high category at -8 m and -7 m GWT and very high category at -6 m GWT. Based on LSI classification, the location belongs to low category at -8 m GWT, and low to moderate category at -7 m and -6 m GWT.