Analisis Kestabilan Lereng Berdasarkan Nilai UCS dan GSI Massa Batuan Yang Dipengaruhi Beban Gempa

Abstract

Construction with earth (rock) excavation work requires good design because the excavation sides will be slopes. The Safety Factor (SF) of the slopes is influenced by several factors, one of which is the Geological Strength Index (GSI), Uniaxial Compressive Strength (UCS) and also the earthquake load. The study aims to find out the GSI values based on Hoek Brown classification, the SF on slopes using earthquake load, and the relationship of the value of GSI with SF using seismic load. The method used in this study is the Bishop method in the limit equilibrium method. The Rock Mass Rating (RMR) stone is obtained from classification based on the conditions of the rocks at the observation site. The GSI value obtained from the equation is the first location is 61, second location is 47, and third location is 60. The value of the SF using the earthquake coefficient (Kh) at the first location is 2.18, second location is 1,77, and third location is 2.22. The SF value obtained is strongly influenced by the GSI value with higher GSI values tending to be followed by higher SF values. However, the increase in the GSI values is unstable for SF where in the second simulation the SF values increased 16,99% from the first simulation, while in the fifth simulation SF values increased 25,1% then the fourth simulation