ANALISIS KESTABILAN LERENG DENGAN METODE BISHOP PADA PENABANGAN NIKEL

Abstract

In a retrieval system of open pit mining, taking nickel ore is closely related to slope stability or bench in the mining area. The aims of this study were to determine safety factors and to recommend the design for unstable slopes. The method used in this study was a bishop method with the standart of safetyvalue was > 1.3. The data requred in this study were the slope geometry, cohesion, density and fraction angle. Of the seven analysed, four A,C,D and F. Were calssified stable with the value of safety factor of 2.19;2.51;2.1 and 2.45 respectively and three unstable conditions; that is slope B, E and G with the value of the safety factor 0.845; 1.20 and 1.11 respecttively. For the three slope, redesign was conducted by increasing the flat distance obtaining the value of the factor of safety be 1.317; 1.317 and 1.302. The research result showed that all the slopes were calssifield stable with the falue of safety factor 1.4- 1.89 except the slope B, E and G is unstable with the value of the safety factor 0.804-1.20 and should be done redesigned the slopes by cut back method by incresing the flat distance;therefore, the falue of safety factor becomes 1.309-1.379.