裂隙岩体渗流场的无单元法模拟及渗流特性研究

    MESHLESS SIMULATION OF SEEPAGE FIELD AND SEEPAGE CHARACTERISTICS FOR FRACTURED ROCK

    • 摘要: 裂隙岩体因含有发育程度不同的裂隙、节理和断层等不连续面,致其渗透性具有各向异性、不连续性等特点,因此传统的有限元法对分布密集的裂隙岩体渗流场求解有一定的难度。本文提出了采用无单元Glaerkin法求解有自由面裂隙渗流问题,并推导了无单元法求解渗流场的基本方程和积分格式,给出了应用罚函数法处理渗流边界条件和自由面处理方法。采用IDL语言编制了二维无单元法计算软件LIDAREFM。文中以北京怀柔桥梓镇某裂隙岩体边坡渗流场计算为例,研究了复杂裂隙共同作用下渗流场特性和自由面分布,讨论了不同开度、不同连通程度的裂隙对渗流场的影响。研究结果表明:无单元法可以较好地解决有密集裂隙的岩体渗流场的求解问题,实现了裂隙处结点任意加密以及积分网格的独立布置,避免了对有自由面和裂隙穿越的子域的重新处理,简化了渗流问题的求解过程。

       

      Abstract: The discontinuities such as cracks, joints and faults can have the varying degrees of developments. The permeability of fractured rock can show the characteristics of anisotropy and discontinuity. The traditional finite element method encounters difficulty in the solution of the seepage field for intensive fractured rocks. This paper proposes the solution of seepage problems with free surface. It is obtained through meshless Galerkin method.the corresponding basic equations and integration schemes are derived. Applications of penalty function method to the processing procedure of seepage boundary condition and free surface boundary are also put forward. Two-dimensional meshless method software LIDAREFM is developed with IDL language. Research on seepage field characteristics and distribution of free surface under different discontinuity combinations are carried out, taking the fractured rock slope at Qiaozi town, Huairou County in Beijing as an example. The seepage field features under different degrees of opening and connectivity are discussed. Results show that the meshless method has certain advantages in solving seepage field of intensive fracture problem. The layout independence of gridding nodes on integration points is achieved. The re-processing of free surface and sub-domain with cracks crossing is avoided. The process of solving the seepage problem is simplified.

       

    /

    返回文章
    返回