Liquefaction potential analysis in Yogyakarta – Bawen Toll Road section 3

The Yogyakarta – Bawen Toll Road construction is one of the National Strategic Projects because it passes through four regencies in Central Java Province and the Special District of Yogyakarta. As the general consideration for infrastructure planning, it was required to consider preventing damages due to natural disasters, including liquefaction caused by an earthquake. The study area has a shallow groundwater table (<10 m), and earthquakes often occurred. Geological conditions showed that the lithologies in Yogyakarta – Bawen Toll Road Section 3 is dominated by silty sand, sandy silt, and gravel. This study aimed to analyze the liquefaction potential in the construction of Yogyakarta – Bawen Toll Road Section 3, especially STA 44+600 – 52+800. The potential liquefaction analysis is calculated using the Simplified Procedure Method based on Standard Penetration Test data. Furthermore, Liquefaction Potential Index (LPI) is applied to determine the level of liquefaction potential. The most central part of the study area indicated no liquefaction potential. On the contrary, the northern and southern parts are indicated to have liquefaction potentials ranging from high to very high. According to the analysis results, it is recommended to have a mitigation plan against liquefaction in the area study.