| The Discontinuous Deformation Analysis (DDA) method is suitable for solving engineering problems with many discontinuous interfaces inside the concerned domain, e.g. the stability analysis of fractured rock mass. The history of various discontinuous deformation analysis methods including DDA is reviewed. The basic theory of DDA is introduced, and the comparisions between DDA and other numerical methods (the finite element methods, the discrete element methods, etc.) are made. Since DDA is still under development, one of concerns is how to improve block displacement functions so that the block stress precision can be improved. Based on the analysis of some related techniques, this dissertation adopts the higher order polynomial functions as the displacement patterns and proposes three kinds of methods for solving the propagation problem of stress in the block. The high order DDA program is developed succussfully. The detailed works are as follows:(1) In order to improve the block stress precision, this dissertation analyzes the the propagation problem of stress in the block and proposes three kinds of methods for solving this problem: the stress coefficient addition method, the stress loading addition method and the block dissection method. The corresponding programs are developed. Severial typical numerical examples are presented which testify these new DDA methods are feasible.(2) Based on the characteristic and the inputing data format of DDA programs, a new program upgrading AutoCAD platform was developed with Visual C++6.0 and AutoCAD ObjectARX developing tools. The code makes the pre-processing and post-processing of DDA more efficient and convenient.(3) This dissertation initially probes into the application of DDA method for the numerical simulation of the deformation and destruction in the whole landslide process.In the end of this paper, the main ideas of this paper are concluded, furthermore, some questions for future studies are put forward. |
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