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水力压裂是许多工程中非常关注的问题,自然情况下的岩体由于经历反复的地质作用往往会形成大量的结构面,结构面的存在影响并制约着岩体的性质.基于颗粒离散元程序对页岩水力压裂进行了数值模拟,采用颗粒粘结模型及光滑节理模型分别模拟完整岩石与节理面,对比分析了完整岩石以及存在节理面的岩体在高压水作用下的裂缝扩展及分布规律.研究发现:对完整岩石进行水力压裂可以获得较为完整的裂缝,且裂缝基本上沿着平行于最大主应力的方向扩展.节理面的存在对页岩水力压裂裂缝的扩展具有诱导作用,数值模拟结果显示除了注水孔周边,裂缝基本上沿着节理面扩展.
Hydraulic fracturing is one of the most concerned problems in many engineering projects. Naturally, the rock masses often form a large number of structural planes due to the repeated geological effects, and the existence of the structural planes affects and restricts the properties of the rock mass.Based on the particle discrete element program The hydraulic fracturing of shale was numerically simulated, and the complete rock and joint surface were simulated by using the particle bond model and the smooth joint model respectively. The fracture propagation and distribution of intact rock and jointed rock mass under high pressure water were compared and analyzed The results show that the fractures can be obtained by hydraulic fracturing of intact rock, and the fractures extend along the direction parallel to the maximum principal stress.The existence of the joint surface can induce the expansion of shale fractures The numerical simulation results show that the fractures extend along the joint plane except for the periphery of the water injection hole.