The Three-dimensional Seepage Analysis And Program Design For The Rock Masses In Fault Zone

There are often a lot of discontinuities in Fault rock masses, including joints, bedding surface, schistosity, fissures, faults, and so on. The seepage problem in discontinuous rock masses is widespread in the human engineering activities, buckling failure of many dam are related to it. With the construction of large-scale water conservancy projects and the development of underground engineering, we often encounter fractured rock mass of different scales, and the seepage influence can’t be ignored. Since the middle of last century, seepage flow in fractured rock mass has always been one of the hotspots in the research of scholars at home and abroad. The methods of seepage research fall into three categories:physical test method, theoretical analysis method and numerical simulation method. Compared with other methods, numerical simulation method is economical, brief, repeatable and programmable. The numerical methods to simulate the effects of the fractures can be classified into three catalogues:including equivalent model, discrete model and hybrid model. Discrete simulation for considering geometric characteristics and physical properties of every discontinuous surface is closer to the engineering practice relative to the equivalent simulation, but caused the difficulty of the preprocess.In order to solve this problem, the equivalent model and discrete model must be reasonably fused, so the composite element method came up. The method considers each discontinuity, but doesn’t consider the spatial geometry of discontinuous in the preprocessing, just put it in the conventional finite element. Then calculate the composite element automatically by the preprocessing program and get a number of sub elements. Its remarkable characteristic is that each composite element may contain a group or several groups of discontinuity, the calculation program can be integrated into conventional finite element analysis.This paper summarizes the model of seepage flow of discontinuous rock mass, making a briefly description in six categories and summarizing their development process and their advantages and disadvantages. Summarize development of composite element method in the stress and strain analysis, seepage, temperature analysis, dynamic analysis and other research. Based on the principle of composite element method and the model of composite element for the seepage flow in fault rock masses, and the effect of fractured thickness is researched. Simplify the tedious and modify the incomplete for the program of composite element method. Then rewrite the preprocessing program of composite element method by MATLAB, at the same time, effectively improve the data storage, read and matrix calculation using the numerical calculation function of MATLAB. Also use the strong drawing function of MALAB to enhance the visual function of the composite element. Finally, the correctness of fault zone rock composite element method is verified the through two examples.