关键词: 水力劈裂, 最大周向应力, 压剪裂纹, 临界水压

Abstract: The application of the hydraulic fracturing technique is more and more extensive in geotechnical engineering, but hydraulic fracturing may cause some geology disasters. Therefore, the mechanism of the hydraulic fracturing is a hot topic in geotechnical engineering. The fracture propagation is studied through the principles of the fracture mechanics, the computation formula of the cracking angle of fracture and the critical internal water pressure based on the maximum circumferential stress criterion are deduced. Then, the relation between the critical internal water pressure and the direction of the fracture are analyzed in detail; meanwhile, the fracture location where the hydraulic fracturing is mostly inclined to occur under the tension-shear complex model is obtained.

Key words: hydraulic fracturing, the maximum circumferential stress, tension-shear complex fracture, the critical internal water pressure