Extended finite element modeling nonlinear hydro-mechanical process in saturated porous media containing crossing fractures
Extended finite element modeling nonlinear hydro-mechanical process in saturated porous media containing crossing fractures
复制标题
含有交叉裂缝的饱和多孔介质中非线性流体力学过程的扩展有限元建模
DOI：
10.1016/j.compgeo.2019.03.006
复制
发表时间：
2019
影响因子：
5.3
通讯作者：
Chen Weizhong
中科院分区：
文献类型：
--
作者：
Yang Diansen;Zhou Yun;Xia Xiaozhou;Gu Shuitao;Xiong Qingrong;Chen Weizhong
本文提出了一种新的计算方法来模拟含交叉裂缝的饱和多孔介质中的非线性流体力学过程。具体而言，分别基于Biot理论和润滑理论推导了力学耦合和传质方程的弱形式。用一种新的结点富集函数描述了t型裂纹周围压力场的弱不连续。采用扩展有限元法（XFEM）对非线性水-力耦合方程进行离散化，并采用牛顿-拉夫逊法进行求解。通过数值结果与解析解的比较，验证了该计算模型的正确性。算例验证了该数值方法的鲁棒性。研究了裂缝取向、基质刚度和围应力对裂缝性多孔介质等效渗透率的影响。数值结果表明，裂缝的相互作用对含交叉裂缝的饱和多孔介质的水力学行为起着至关重要的作用。
A novel computational methodology is proposed in this work to simulate the nonlinear hydro-mechanical process in saturated porous media containing crossing fractures. Specifically, the weak form of mechanical coupling and mass transfer equations is derived based on Biot’s theory and lubrication theory, respectively. The weak discontinuity for pressure field around T-shaped crack is described by a new junction enrichment function. The nonlinear hydro-mechanical coupled equations are obtained by Extended Finite Element Method (XFEM) discretization and solved by Newton-Raphson method. This proposed computational model is verified by comparing numerical results with analytical solution. The robustness of this numerical method is demonstrated by several examples. The effects of crack orientation, matrix stiffness, and confining stress on the equivalent permeability of fractured porous medium are investigated. Numerical results indicate that the interaction of cracks plays a critical role on the hydro-mechanical behavior of the saturated porous media containing crossing fractures.