关键词:  关键块体, 失稳概率, 节理交切概率

Abstract: The failure of slope is generally caused by the destabilization of key block which lead to the conducive chain reaction of failure. So the key block is the core factor affecting the stability of slope. The block failure probability, which was related to two parameters: the joint intersection probability and the JP instability parameter to evaluate the stability of the key block. And then, the connectivity rate of rock structural surface was adopted to revise the joint intersection probability. The revised joint intersection probability could reflect the size and discontinuity of structural planes. The result shows that the failure probability of the key block could be evaluated with the block failure likelihood which can provide the basis for the design of rock slope support.

Key words: Key block, Failure likelihood, Joint intersection probability