Liquefaction potential analysis in Palu Bay area

Abstract

Sulawesi Island has a Palu Koro Fault that actively moves with a high displacement magnitude but low seismicity. On 28 September 2018, at 18:02 local time, an earthquake occurred in Palu Koro Shear Fault. The field investigations along the Palu coast revealed new evidence regarding the extensive liquefaction in these areas, both inland and coastal land. The research command area was located in the Palu Bay coastal area, the Province of Central Sulawesi. The data used was in the form of the Standard Penetration Test of the area, and the potential liquefaction analysis was carried out using the simplified procedure method. Furthermore, to determine the level of liquefaction potential, Liquefaction Potential Index was applied. Geological observations showed that the soil condition in the Palu Bay area was dominated by non-cohesive soil (sand). Based on the liquefaction potential analysis, it was indicated that most of the eastern region of the Palu Bay area showed no liquefaction potential. On the contrary, the western and southern parts were indicated to have liquefaction potentials. The Liquefaction Potential Index analysis results showed that the western and southern areas were dominated with extremely high liquefaction potentials. Meanwhile, in the eastern area, it was extremely low.