Application of stone column method for liquefaction mitigation in Palu Bay area after the 2018 Palu earthquake

Abstract

On 28 September 2018, an earthquake occurred on the north-south Palu Koro shear fault, extending through Palu City and other cities in Central Sulawesi Province, Indonesia. In addition to the tsunami, the event triggered liquefaction not only on the land but also in the coastal area. Thus, mitigation efforts to prevent potential disasters in Palu Bay coastal area are required. This research covered the Palu Bay coastal area, Central Sulawesi Province and conducted through the core drillings and Standard Penetration Tests on the area. Low liquefaction potential was achieved through soil improvement by applying stone column method based on the specified criteria. Mitigation effort on the liquefaction hazards comprised of stone column method which applied the Priebe's calculation method. The mapping result indicated the need for stone columns with deeper and closer spacing distance on the western and southern areas than those in the eastern areas. Due to the wide variety of stone column designs resulted from the mitigation analysis, simplification stone column designs was made to facilitate the construction implementation.