Settlement Analysis in Potentially Liquifiable Soil at Kretek 2 Bridge Area

The Kretek 2 Bridge is one of the important infrastructures built on the southern coast road of Java. Referring to the Map of Indonesia Liquefaction Vulnerability Zone in 2019, Kretek 2 Bridge was identified as a high liquefaction susceptibility zone. The result of liquefaction potential analysis on the slab-on-pile section indicates that the soil layer has potential to liquefy if an earthquake occurs. Based on the Liquefaction Severity Index, the slab-on-pile section of the Kretek 2 Bridge has a high severity index at BH-10, moderate severity index at BH-11, and low severity index at BH-01 and BH-12. One of liquefaction effects is a ground settlement. Settlement due to liquefaction is a vertical soil deformation in the soil layer caused by compaction due to the earthquake. This study was conducted by calculating the settlement of sand deposits in slab-on-pile section using an equation proposed by Zhang et al. in 2002 and Yoshimine in 2006. The results of settlement analysis using Zhang’s method to predict settlement in the study area, BH-10 having the most significant settlement at 29.803 cm. Using the settlement analysis method by Yoshimine, the highest settlement found in BH-10, which is 30.401 cm.