Study of Palangpang Bridge Foundations in the Area Potential to Liquefaction Throughout the Cimandiri Fault A K Somantri (a), Iskandar (a), A Febriansya (a*), B A Daffa (b), R I Hermawan (b)
(a) Civil Engineering Department, Politeknik Negeri Bandung, Jln. Gegerkalong Hilir, Ds. Ciwaruga, Bandung, Indonesia
*aditia.febriansya[at]polban.ac.id
(b) Student of Civil Construction Study Program, Civil Engineering Department, Politeknik Negeri Bandung, Jln. Gegerkalong Hilir, Ds. Ciwaruga, Bandung, Indonesia
Abstract
Liquefaction is a phenomenon that occurred due to loss of shear strength of soil caused by earthquake. In general, liquefaction happened during earthquake with big magnitude, on very loose to loose sand, and high ground water level. Palangpang bridge is located in Ciwaru area, Sukabumi district, West Java province, Indonesia and located over the Cimandiri fault. According to the history of seismicity in the area of Palangpang Bridge were having experienced earthquake up to 25 times in the last 50 years. In this paper, liquefaction potential analysis at the bridge foundation will be conducted with qualitative and quantitative method. Based on the cone penetration test (CPT) result, in the area of Palangpang Bridge, the soil layer that withstand the load of bridge is alluvium soil with beach sand sediments, and the ground water level was 2.5-3.0 meter below ground surface. The result of liquefaction potential analysis shows that the soil layer at the depth of 9 meter below surface were having liquefaction, so that the foundation of Palangpang Bridge needs to be reinforced. Reinforcement design were to add 8 piles to the existing pile configuration for each footing so that the bridge can operate safely.
Keywords: arthquakes, Liquefaction, Cyclic Resistance Ratio, Cyclic Stress Ratio
