Foundation resistance analysis of Cisomang Bridge

Abstract

Cisomang bridge is one of the bridges connecting Jakarta and Bandung through Cikampek-Padalarang (Cipularang) Highway. The Road and Bridge's Research and Development Centre (PUSJATAN) presents data that on December 23rd, 2016 Pier P2 of Cipularang Highway is shifted for 57,02 cm. This movement is suspected occurred due to decreasing of clayshale's shear strength caused by Cisomang River's seepage. Pier P2 movement is indicating lateral displacement of Cisomang Bridges foundation for 22 m deep which dominates the total displacement when compared to its settlement. Accordingly, we study trough back analysis method for determining the impact of bore pile reinforcement to lateral displacement on clayshale using PLAXIS to simulate the behaviour of soil. This research proposes 35 m and 60 m depth bore pile to be a foundation reinforcement. Aside from its contribution on decreasing lateral displacement of existing foundation up to 33-68%, this reinforcement cuts the slip surface of Cipularang slope and increases its safety factor (SF) for 4,7-16%.