裂隙网络无压渗流分析的初流量法

Initial flow method for unconfined seepage problems of fracture networks

借鉴初流量法的思想,引入初流速来抵消在裂隙网络干区实际不存在的流速,将Darcy定理扩展到整个区域,定义了在整个区域上的非线性边值问题,并将潜在溢出面边界条件归纳为Signorini型边界条件,建律了等价的变分不等式提法。通过结合连续型的Heaviside函数,给出了基于变分不等式的初流量有限元迭代算法,研制开发了相应的计算程序,通过两个典型算例验证了本文算法在求解复杂裂隙网络渗流自由面的有效性和鲁棒性。

Based on the idea of the initial flow method,initial velocity is introduced to eliminate the velocity that does not exist in dry zone.Darcy formula is extended to the entire region and a nonlinear boundary value problem of the entire region is defined.Through categorizing the potential seepage face as a boundary condition of Signorini’s type,an equivalent variational inequality is established.By combining the continuous Heaviside function,a finite element iterative algorithm of the variational inequality based on initial flow method is given.With this algorithm,a program is developed.Two typical examples are employed to demonstrate the efficiency and robustness of the algorithm proposed here in locating the free surface of complex fracture networks subject to underground water.