PROBABILITY OF SLOPE DESIGN FAILURE ANALYSIS ON OPEN PIT NICKEL MINE, PT XYZ IN EAST HALMAHERA , NORTH MALUKU

• Main Author: Febrian, Andika
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40345
• Institution: Institut Teknologi Bandung

PT XYZ is a nickel mining company located in East Halmahera, North Maluku which intends to find out geometric recommendations regarding single slopes and overall slopes at the end of the mine. Geotechnical study is needed regarding the geometry of the slopes to be formed. Based on the Minister of Energy and Mineral Resources Decree Number 1827 K / 30 / MEM / 2018, an analysis of the probability of slope landslides needs to be done to determine whether the slope is safe or not. This study aims to determine the slope design recommendations that are safe from possible landslides and find out the probability values of landslides in the overall slope design and single slopes that have been made. Landslide probability analysis is done by calculating the security factor from the slope design that has been made as much as 1000 times. Material characteristics are generated randomly with Monte-Carlo simulation method in Slide 6.0 software which is also used to calculate slope safety factors. This random generation is based on input parameters which contain the distribution of material characteristics along with the average value, the standard deviation value, and also the maximum and minimum relative values. This distribution is obtained through processing the Goodness of Fit with the Kolmogorov-Smirnov method and the Akaike Information Criterion test on cohesion data, deep friction angles, and the contents of the slope constituent material. From the results of the analysis, the recommendation of a single limonite slope geometry is 3 meters high and 50o slope angle for the four cross sections in the safe category at all FK sor 1 landslide severity levels with PK 25-50%. The recommendation of a single saprolite slope geometry is 6 meters high and 50o slope angle for the four cross sections in the safe category at all FK sor 1 landslide severity levels with PK 25-50%. Then the geometry of the single bedrock slope was 6 meters high and 70 ° slope angle for the four cross sections in the safe category at all landslide severity levels. From the results of the overall slope probability analysis, it is known that four cross sections with innate slope geometry are not safe in all landslide severity conditions in accordance with the provisions of minimum PK ? 20%. or saprolite which is not in accordance with the conditions of the slope, changes the overall slope angle, changes the geometry of the bedrock slope with a height of 6 meters and angle of slope 70o. After changes to the overall slope design, the PK values on the overall slopes of sections 3 and 4 are declared safe in all levels of landslide severity with a PK value of <5%. The overall cross section of slope 1 was declared safe in the severity of medium landslide PK <10% and the overall slope of cross section 2 was declared safe in the severity of kelonsorang low PK 15-20%.