LANDSLIDE PROBABILITY IN THE EAST ASAM DUMP IN PIT AREA OF PT ARUTMIN INDONESIA CONCESSION AREA ASAMASAM MINE, SOUTH KALIMANTAN

Muhammad Akmal  Fahrezi; Zulfiadi Zakaria; Nur Khoirullah; Prima Laksana

doi:10.30556/imj.Vol28.No1.2025.1628

Authors

Muhammad Akmal Fahrezi Universitas Padjadjaran
Zulfiadi Zakaria Faculty of Geological Engineering, Universitas Padjadjaran
Nur Khoirullah Faculty of Geological Engineering, Universitas Padjadjaran
Prima Laksana Faculty of Geological Engineering, Universitas Padjadjaran

DOI:

https://doi.org/10.30556/imj.Vol28.No1.2025.1628

Keywords:

disposal area, slope stability, slope failure probability, slope stability simulation

Abstract

Open pit mining involves excavation of soil and overburden, which requires a well-planned disposal area to maintain stockpile stability. This is achieved through an analysis of soil bearing capacity and slope stability. The research was conducted at the ASTIM In Pit Dump (IPD) using actual materials. Data were obtained from direct shear tests and physical properties tests, then statistically analyzed to determine the average value, standard deviation, and minimum and maximum relative values. These data were subsquetly input into geotechnical software to perform a slope stability analysis under pessimistic conditions, including water-saturated slopes with a horizontal seismicity coefficient of 0.045. The simulation results did not meet the stability criteria, yielding a safety factor of 0.647. Therefore, engineering design modifications were necessary, including widening the slope angle to 7.61°, consisting of six steps with a level height of 5 meters, a width of 30 meters, and a slope angle of 25°. This redesign resulted in a safety factor (SF) of 1.254 which meets slope stability criteria based on Bowles (1989) and a probability of failure (PoF) of 4.1%, in accordance with the Decree of the Minister of Energy and Mineral Resources No. 1827 K/30/MEM/2018.

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