PROBABILISTICS OF PLANE FAILURE USING MONTE CARLO SIMULATION IN SLOPE STABILITY ANALYSIS WITH LIMIT EQUILIBRIUM METHOD IN OPEN MINE PT XYZ

• Main Author: Farhan, M.Alfiza
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40257
• Institution: Institut Teknologi Bandung

The stability of a slope in mining activity is strongly influenced by geology, especially the rock properties and geological structures. Slope stability analysis will be faced with several problems on the uncertainty of rock properties and rock mass. Slope stability analysis are simply using concept the value of Safety Factor (SF), using a single value on each input parameter while the probabilistic methods offer a more systematic way in treating conditions of uncertainty and provide an alternative to the approach the value of the safety factor that is information the Probability of Failure (PF) a slope. The purposes of this study are to determine the value of deterministic safety factors on the slopes of PT XYZ open pit, determine the probability of plane failure from a Monte Carlo simulation on the slopes of PT XYZ open pit, determine the optimum safety factor value from the acceptable probability of failure. There are three locations that have the potential to occur plane failure, namely location 11, location 43 and location 61. SF deterministic with limit equilibrium Hoek and Bray method produces a value of 2,134 at location 11, 0.771 at location 43 and 1,912 at location 61. While the value of SF deterministic with limit equilibrium Janbu method produces value of 0.974 at location 11, 0.529 at location 43 and 1,188 at location 61. PF obtained from the safety factor calculation with limit equilibrium of Hoek and Bray using Microsoft Excel software is 0% at location 11, 69.25% at location 43 and 0.02% at location 61. PF obtained from the safety factor calculation with limit equilibrium of Janbu using Slide 6.0 software is 57.36% at location 11, 99.8% at location 43 and 8.6% at location 61. Location 11 needs to be changed the slope angle to 45o so that the optimum SF value that can be received is 1.149 with PF 5.25%. Then at location 43, it is also necessary to change the slope angle to 43o so that the optimum SF value that can be received is 2.209 with PF 4.97%. Location 61 already has acceptable PF criteria.