Analysis of the Influence of Groundwater Level on Slope Stability at Highwall PT. X, South Kalimantan

Abstract

Mine slope design is an important part of mining operations because it is used to determine the balance between mine economy and operational safety. In the mine slope design there will also be a groundwater level design, the groundwater level is one of the triggers for a slide to occur. Therefore, this study aims to determine the effect of the groundwater level on the stability of the highwall slope cross section A-A’ as well as to determine the factor of safety value and probability of slope failure under various conditions of high groundwater levels. This research method uses quantitative methods because there are numerical data that will be used to calculate the value of slope stability. Slope stability analysis uses the “morgenstern-price” boundary equilibrium and the “monte-carlo” landslide probability. From the research results it is known that the higher the groundwater level, the lower the safety factor value because the presence of groundwater can reduce slope stability causing a decrease in soil shear strength due to increased pore water pressure. In addition, the weight of the material will increase due to the presence of groundwater, which causes the driving force on the slope to also increase. In addition, the movement of air in the soil can cause seepage forces which can affect slope stability. The lowest safety factor value is at the groundwater level 100% of the overall slope height, in conditions of 100% of the overall slope height, the deterministic safety factor value is 1.337, the mean safety factor is 1.358, and 0% hazard susceptibility.