裂隙岩体的渗流-损伤耦合分析模型及其工程应用

A coupled seepage-damage analysis model for jointed rock masses and its application to rock engineering

本文对裂隙岩体中的渗流提出一种渗流-损伤耦合分析模型,这个模型将岩体中的裂隙模拟为具有一定张开度的扁平圆盘裂纹,由现场裂隙统计分析和计算机Monte Carlo法产生随机裂隙网络系统,计算裂隙的空间连通率,对其力学行为,运用损伤断裂力学模型予以描述。本文阐述了渗流对裂隙岩体的力学作用和岩体的应力状态对裂隙渗透特性的影响,根据不同应力状态下,裂隙的损伤断裂扩展过程建立起渗透张量的演化方程。最后提出了有限元分析程序并将其应用于工程实践。

To deal with the seepage in jointed rock masses, a coupled mechanical-hydraulic analysis model is developed in this paper. According to this model, the jointed rock mass, to be treated as an anisotropic, porous damaged medium with the corresponding elastic compliance and permeability tensors, is hydraulically equivalent to the discontinuous mass. The mechanical behaviours of the medium are described by a fracture damage model, while the hydraulic equivalents are formulated on the assumption that joints in rock masses can be reproduced by a set of parallel planar plates. To estimate the interconnection between joints, a series of stochastic crack networks are established by computers with Monte Carlo technique on the basis of in-situ observation and statistical procedures to characterize joint orientation. The effect of seepage on mechanical behaviour of joint et rock mass and the effect of stress states in rock masses on its conductivity are discussed in detail. According to the processes of joint crack propagation under different stress states in rock masses, a set of evolution rules governing the permeability tensor variation are established. Finally, a numerical analysis FE-program with the coupled model proposed above is developed and applied to the rock engineering.