Liquefaction Hazard Potential and Ground Failure Probability Analysis in the New Access Road at Rendani Airport, Manokwari, West Papua, Indonesia

Abstract

According to data from the United States Geological Survey (USGS), the Manokwari region in West Papua Province experienced a 7.6 Mw earthquake in 1944, approximately 5 km from Manokwari City. Potential consequences of such an earthquake is liquefaction, which may occur at the Relocation Plan of the Access Road at Rendani Airport, characterized by shallow groundwater and loose soil. This study aimed to assess the distribution of the Liquefaction Potential Index (LPI) and Ground Failure Probability (PG) using Standard Penetration Test (SPT) data from 18 sampling locations. This was achieved by comparing Peak Ground Acceleration (PGA) values derived from both Deterministic Seismic Hazard Analysis (DSHA) and Probabilistic Seismic Hazard Analysis (PSHA) methods. Determined PGA values of 0.449g for soft soil and 0.499g for medium soil that also can be used as reference in Manokwari area which influenced with Sorong Fault. The LPI value ranged from 0 to 27.06, including a very high potential category at 8 locations, primarily in the northern area, while the PG values greater than 0.9, categorized as very high and almost certain to occur, were identified at 13 locations, also mostly in the northern region. Based on these results, it is essential to consider this liquefaction potential when designing the infrastructure to be built in Manokwari, especially around Rendani Airport.