裂隙土等效连续介质的渗透张量及表征单元体积

Permeability Tensor and Representative Elementary Volume of Equivelent for Cracked Soil

裂隙土的渗透特性是裂隙土边坡稳定性分析中重要的参数。文中通过分别考虑随机裂隙网络和土体本身的渗透性,推导裂隙土的渗透系数,并用张量的形式表示渗透系数的各向异性。同时建立了确定裂隙土表征单元体积的准则,为应用等效连续介质模型提供了基础。结果表明裂隙土的渗透系数大于裂隙网络和土体的渗透系数,其渗透方向取决于裂隙网络的渗透方向。算例中裂隙土的表征单元体积大约是裂隙长度平均值的5倍。

Permeability is an important parameter for analysis on stability of slopes.The permeability of a cracked soil is derived by considering the permeability of a random crack network and of soil mass separately in this paper.A permeability tensor is used to demonstrate the anisotropy of the cracked soil.In addition,a criterion is established to determine the representative elementary volume（REV） of the cracked soil.Results show that the value of permeability of the cracked soil is larger than those of the crack network and soil mass.The permeability in the crack network dominates flow in the cracked soil.The REV of the cracked soil in the example is about 5 times of the mean crack length.