Penggunaan metode LPI dalam menganalisis potensi likuefaksi di Kota Palu dengan lima variasi nilai M w

Abstract

Liquefaction is the behavior of soil in which soil in saturated soil decreases and strength decreases due to increased pore water pressure during soil vibration caused by an earthquake. If the liquefaction potential is not properly calculated during infrastructure construction, changes in ground strength during an earthquake can cause infrastructure to collapse or deteriorate. A liquefaction event in the city of Palu caused the ground surface to shift and sink, destroying infrastructure in the area. Based on this, the liquefaction potential of Palu city should be thoroughly analyzed in order to determine the liquefaction risk before construction. A simplified method proposed by Seed & Idriss (1971) calculates the value of the factor of safety (FS) based on the SPT data by comparing the values of CSR (Cyclic Stress Ratio) and CRR (Cyclic Resistance Ratio). Iwasaki et al. (1978, 1982) continued the simplification using the liquefaction potential index (LPI) method, providing results in the form of predictions of soil layer performance and liquefaction potential of the soil surface. As a result of analysis using the LPI method, it was found that Palu City is an area with the potential for liquefaction with different LPI values for each location. Point B-1 is a very high liquefaction potential point with LPI value of 66.11 under the condition of Mw 7.5. An increase in the magnitude of an earthquake will affect the magnitude of LPI value. The larger the size scale, the larger LPI value analyzed.