Abstract: Based on the properties of surrounding rock in deep chamber , the phenomenon of fracturing mechanism of sur rounding rock in deep chamber was analyzed by fracture dynamics , from the perspective of microcosmic fracture. SUITounding rock in deep chamber had three characteristics; high in-situ stress , high seepage pressure and high temperature. In the calculation , the common effect of high in-situ stress and high seepage pressure were considered , and a wide definition of critical intemal water pressure was introduced. And then the relation between the critical intemal water pressure and th巳direction of the fracture under tensile-shear was analyzed. Test results show that the max generalized critical water pressure is obtained at the direction angle of the fracture β= 55 0 under tensile-shear , and the generalized critical water pressure changes with the grotto azimuth angle and lateral pressure coefficients.

Key words: hydraulic fracturing, fracture theory, surrounding rock in deep chamber, the critical intemal water pressure

摘要： 基于深埋围岩洞室的特性，运用断裂力学原理，从微观断裂的角度分析了深埋围岩洞室水力劈裂现象;基于深 部围岩所处的高地应力、高渗透压力、高温特性，在计算时考虑了高地应力与高渗透压力的共同作用;引人广义临界 水压力，分析了拉剪及压剪复合断裂时11负界水压力与裂纹面方向之间的关系。研究表明:在压剪复合状态下最大广 义临界水压力在原裂纹方向角β=55。取得，广义临界水压力随着所处洞室方位角及侧压力系数的变化而变化。

关键词: 水力劈裂, 断裂理论, 深埋围岩洞室, 临界水压