Analysis of Liquefaction Potential Based on The Grain Size Distribution of Soils and Cone Penetration Test (CPT) Data

Abstract

Liquefaction is a failure phenomenon in the soil layer which generally occurs due to cyclic loads from earthquakes. This study was conducted to determine the potential for liquefaction based on soil grain size distribution and CPT data in the UII Hospital area in Wijirejo Village, Bantul, DIY. Based on its geographical location, the Bantul district has a high earthquake potential because it is near an opak fault and is located in a subduction zone between the Indo-Australian Plate and the Eurasian plate. Along with this, there is urgency for this research. Analysis based on the grain size distribution of the soil was evaluated using the Tsuchida curve (1970). Analysis based on CPT data was evaluated using the Seed & Idris (1971) and IM Idriss & RW Boulanger (2008) equations to obtain a soil layer safety value, which was then used to predict the level of potential liquefaction with the LPI value using the Luna & Frost (1998) equation. Based on the grain size distribution using the Tsuchida curve (1970) in Wijirejo Village, the soil layer at a depth of 1 meter is dominated by sandy soil and silt, which has liquefaction potential. Based on CPT data, all sondir points have a very high liquefaction potential with consecutive LPI values 48,405; 52,160; 57,498; and 46,942 with a potential liquefaction zone depth of 0.20 to 13.20 meters from the ground level.