Numerical Analysis Of Unsaturated Seepage Through Fracture Network In Rock Mass During Rainfall

The increasing severity of slope failure and dam failure, make the unsaturated seepage through fracture network one of the key issues. Based on the review of national and international research on unsaturated seepage through fracture network, the characteristics of unsaturated seepage through fracture network, concept models, mathematical models, constitutive relations and the theoretical models are summarized and established. Major findings are as follows:1. The concept models and mathematical models for unsaturated seepage through fracture network during rainfall are just only the application of models to the fracture network seepage; at the same time they are associated each other, the form one is the foundation of the later one, and the later one is the quantitative reflection of the former one. Each mathematical model is an independent one, they are relative with others and foundation to others, and each one has its own characteristic and applicable scope.2. The curves of constitutive relation of the unsaturated seepage through fracture network are mainly based on the capillary channel theory, not considering the matrix suction, and there are not curves which can reflect the other characteristics of the unsaturated seepage through fracture network hardly; the experimental results, which are summarized from many other researches, are used during seepage simulation, so that the costs is reduced, and the research are continued all right, at the same time, the studied results are used sufficiently; during choosing the curves, we should choose the appropriative model of curves according the different distribution of the fracture network; all the curves in the papers are used in the situation not considering the stress on the fracture, the results just only reflect the basic characteristics of the unsaturated seepage through one single fracture under not considering the stress, the experimental researchs about the drainage and sucking process in the single unsaturated fractured considering the complex stress should be studied; the concluded curves all are experienced one following the pore medium model, but the practical seepage through fracture are more complex, so the concluded models need to be tested by more experiments.