Evaluation of liquefaction potential in flow liquefaction area in Palu City after the 28th September 2018 Donggala-Palu Earthquake

The occurrence of flow liquefaction phenomena, locally termed Nalodo, during the Donggala-Palu earthquake on 28 September 2018 destroyed some residential areas and infrastructures in Palu City and Sigi Regency. Evaluation of liquefaction potential in the flow liquefaction areas is required to assess the liquefaction susceptibility of the area to future earthquakes. This paper presents the results of liquefaction potential analysis in the Balaroa, and Petobo areas based on the SPT method. A calculated peak ground acceleration was used for each location. Based on the analysis, all the liquefied soil layers are still liquefiable, especially in the Balaroa area, causing a significant ground settlement. These results imply that flow liquefaction areas are still susceptible to liquefaction during a big earthquake event. Thus, restriction of re-inhabitants in the liquefaction areas is necessary, and the infrastructure development in the areas requires a proper engineering design to mitigate earthquake-induced liquefaction hazards in the future.