Post liquefaction effect on 1 and 2-dimensional model: a case study of Pasigala raw water transmission structure

Abstract

Abstract The Liquefaction phenomenon that occurred in Central Sulawesi in September 2018 was triggered by a powerful earthquake that caused extensive destruction and loss of life. Due to its location close to the most active fault in Central Sulawesi, Palu Koro fault, there is still a high probability of recurrence of liquefaction near the area. Ikhsan et al (2023) found that near Sigi regency, certain spots are susceptible to liquefaction occurrence, especially near Maranatha village. This research aims to find the effect after the liquefaction near the Pasigala raw water bridge transmission construction in Sigi Regency if a similar earthquake occurred. It needs to be done because Pasi gala raw water transmission is one of the main raw water supplies to central Sulawesi. Some geotechnical data were carried out in this research such as stratigraphy, SPT, groundwater level, and seismic data. The Post liquefaction analysis was carried out using Idriss and Boulanger (2008) to define one-dimensional settlement potential from the spatial distribution of the liquefaction zone. Numerical models were compared to analyze the settling behavior in a two-dimensional model. The Empirical and Numerical results indicate that the settlement near the abutment’s structure over the 2018 earthquake simulation exceeded the permissible limit of 15 centimeters. This finding may lead to the prediction of damage to the entire structure.