SLOPE STABILITY ANALYSIS OF ROCK MASS ON PLTU SURALAYA ROAD, CILEGON CITY, BANTEN PROVINCE

• Main Author: Alfath Salvano S, M
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/70397
• Institution: Institut Teknologi Bandung

PT. Indonesia Power planned to build additional power plants unit at the Suralaya Power Plant. The construction of the power plant requires a diversion road to be built at the southern part of the area. The road will cut through the hills with a height of up to 65 meters above sea level. Geologically, the rock units found at the location are part of volcanic products of Gede which consist of andesitic lava deposit and pyroclastic breccia with intensive joints. The joint condition has significant control in excavated slope stability. A study is required to determine the stability and support recommendations of rock mass slope alongside Suralaya power plant road. The research area has excavated slopes of 70°-75°. The geological engineering unit found at the location consist of Andesite 1 Unit, Breccia Unit, Lapillistone Unit, Andesite 2 Unit and Alluvium Unit. Field observations showed that eight slopes have the failure potential, namely SC-1 to SC-8. The engineering properties of rock was obtained from laboratory and field testing. Discontinuity characteristics were obtained using scanline techniques on the rock outcrops at the field. Characterization of rock mass using the Rock Mass Rating Method is done to determine the quality of rock mas. The rock mass class obtained is II - III (good rock - fair rock) with a value of 58-75. Kinematics analysis is performed to determine the type and position of the failure. The kinematic analysis shows the type of toppling failure for SC-3 and wedge failure for other slopes. Slope stability and support recommendations analysis are based on the Slope Mass Rating method, which is a modification of Rock Mass Rating with the results of kinematics analysis. Slopes with class IIb (stable) is at SC-1, SC-5, SC-6 and SC-8. Class IIIa slope (partially stable) is at SC-2 and SC-7, and Class IIIb slope (partially stable) is at SC-4 and SC-3. Support recommendations include toe ditch, nets, bolting/anchor, shotcrete, toe wall, and dental concrete with an installation that is adjusted to the slope stability class based on SMR.