基于近场动力学与有限体积法耦合的裂隙岩体渗流模拟

Seepage Simulation Method of Fractured Rock Mass Based on Coupling of Peridynamics and Finite Volume Method

摘要:

考虑在不降低求解精度的情况下有效地减少计算量，基于有效应力原理提出了一种有限体积法与近场动力学耦合的方法来模拟饱和孔隙裂隙介质中水力裂缝扩展问题。首先，通过多孔介质渗流模拟算例验证了所提方法的有效性；其次，通过几个数值算例进一步验证了该方法在流体驱动下模拟饱和裂隙孔隙介质中裂纹扩展的能力和主要特点；最后，通过对5个工况的模拟，展现了围压差对水力压裂裂缝扩展具有诱导作用的现象。同时，将该耦合方法的数值模拟结果与其他数值、解析结果或试验结果相对比，进一步说明所提出的耦合方法能够有效模拟岩石流固耦合的力学扩展破裂过程。

Abstract:

Considering effectively reducing the amount of calculation without reducing the solution accuracy， and based on the principle of effective stress， a coupling method of finite volume method and peridynamics is proposed to simulate the hydraulic fracture propagation in saturated porous fractured media. First， the effectiveness of the method proposed is verified by a porous media seepage simulation example. Then， the ability and main characteristics of this method to simulate crack propagation in saturated fractured porous media driven by fluid are further verified by several numerical examples. The simulation of five working conditions shows that the confining pressure difference can induce the fracture propagation of hydraulic fracturing. At the same time， the numerical simulation results of the coupling method are compared with other numerical， analytical， or experimental results， which further indicates that the coupling method proposed can effectively simulate the mechanical propagation and rock fracture process.