渗流应力耦合下含裂缝页岩力学特性和破坏模式研究

为研究在渗流应力耦合作用下含裂缝页岩的力学性质以及破坏模式，利用岩石破坏过程分析系统RFPA2D-Flow，建立7组含不同角度预制裂缝的页岩模型，并对其破裂过程进行了数值模拟。研究表明：页岩的破裂过程分为线性变形、屈服变形以及完全破坏三个阶段，源于裂缝的存在，页岩的弹性模量和抗压强度均表现出明显的各向异性的特点，且试样的最终破裂模式可分为斜线型、X型、λ型与崩坏型四种。对于不同层理倾角下的裂纹分布，渗流—应力耦合作用下页岩试样的破坏主要是拉伸破坏，并伴随着剪切破坏，其中试验表明，当α=90°时，试样所受的剪切破坏最严重。该研究结果对页岩开采具有重大的意义。

Research on the Mechanics Properties and Failure Modes of Crack- containing Shales Coupled with Seepage Flow Stress

In order to study the mechanical properties and failure modes of fractured shale under the seepage stress, the rock failure process analysis system RFPA2D-flow was used to establish 7 groups of shale models with prefabricated fractures at different angles and the fracture process was numerically simulated. The results show that the fracture process of the shale can be divided into three stages: progressive linear deformation, yield deformation and complete failure. Due to the existence of fractures, the elastic modulus and compressive strength of the shale show distinct anisotropic characteristics and the final fracture mode of the sample can be divided into four types: slash-type, X-type, λ-type and collapse-type. For the crack distributions under different bedding inclinations, the fracture of the shale sample under the coupled percolation-stress is mainly tensile failure accompanied by shear failure, and the test shows that the shear failure of the sample is most serious when α =90°. These results have important implications for shale exploitation.