Rock slope stability comparison between deterministic and probabilistic block theory analyses for an open pit mine
The ultimate slopes of an open pit mine are generally excavated to the steepest possible angle because the economic consequences of the excavation angle are significant.For large scale open pits,changes in slope angle by approximately 2–3 degrees may correspond to hundreds of millions of dollars in project value.However,steeper slope angles result in an increased probability of slope failure.Therefore,it is critical to calculate the maximum safe slope angles(MSSA)and also to estimate probabilities of slope failure with respect to different cut slope dip angles.The block theory is a very useful technique to investigate possible failure modes of rock blocks and to determine MSSA for rock slopes.The block theory considers block formation by discontinuity planes along with a cut slope,without assuming presence of lateral release planes as in kinematic analysis.Therefore,the results obtained from the block theory analysis can be considered to be closer to the reality than that coming from kinematic analysis.However,block theory is usually used to perform deterministic analysis using single fixed values(typically mean values)to represent orientation of discontinuity sets and strength parameters.The open pit mine slope stability is one of the mining subjects dominated by variability and uncertainty because the slopes are composed of natural heterogeneous materials containing many discontinuities.In discontinuous hard rock masses,the variability and uncertainty of rock slope stability analyses mainly arise from discontinuity geometry and strength.Therefore,it is important to incorporate the said variability and uncertainty in performing block theory analysis.This requires developing new formulations to perform probabilistic block theory analysis and comparing the results obtained between deterministic and probabilistic block theory analyses.
Pinnaduwa H.S.W.Kulatilake Jun Zheng Biao Shu Taghi Sherizadeh
Rock Mass Modeling and Computational Rock Mechanics Laboratories, University of Arizona
国际会议
The 12th International Conference on Analysis of Discontinuous Deformation(第12届非连续变形分析国际大会)
武汉
英文
58-58
2015-10-16（万方平台首次上网日期，不代表论文的发表时间）