The condition of upper soil layer that causes severe damage to land due to liquefaction

Abstract

An evaluation using the liquefaction potential index (LPI) was still applicable to the site conditions in Central Sulawesi in 2018's earthquake with Mw 7.5. In some areas, severe liquefaction occurred and destroyed many buildings. This study was conducted to determine the depth of the liquefaction layer in any soil conditions that may cause severe damage to the land. This is intended to obtain guidance to select an area for housing, especially for low-budget housing. The possibility of land severely damages due to liquefaction occurred when the LPI value was more than 15. The analysis was conducted by creating various models of soil lithologies using the simplified procedure based on the standard penetration test (SPT) data. The upper layer was designed to have liquefaction potential, while the lower layer had not. The results were presented in graphs of correlation of the upper layer depths with the LPI greater than 15 using the N-SPT data ranging from 5 to 20 with a fines content (FC) of 5%, 15%, and 35%. Based on these results, selecting a safe location for housing could be done easily to prevent a massive disaster in the future.