摘要
The investigation of the unstable rock blocks, the evaluation of their stability and their prevention measure are difficult tasks. In this paper, in order to treat the unstable rock blocks, a stability evaluation criterion for unstable rock blocks at Nanmenwan is established on the basis of the study of the W6 unstable rock block with stereographic projection method. At the same time, the stability zone division at Nanmenwan is carried by the analysis of rock fractures development. At last, the control measures for unstable rock are also proposed.