Study On The Realization Of Three-dimensional Limit Equilibrium Analysis Of Landslide Stability

Up to now, the research of two-dimensional limit equilibrium analysis of landslide stability has developed a lot, but it is quite a big simplification to put up an analysis of landslide stability with few two-dimensional section planes instead of the real three-dimensional landslide body, and the influence of transverse boundary is ignored, so problems always appear in the result of analysis. Three-dimensional model can reflect the condition of the landslide much closer to the real situation, however, there are quite a lot of difficulties in both modeling and calculation, so it is very significant and valuable for us to develop an available method for three-dimensional limit equilibrium analysis of landslide stability.In this paper, the author analyzes some problems and gets some conclusion as follows:(1) The author introduces an all-purpose model for three-dimensional analysis of landslide stability. Then, on the basis of this model, the author establishes the expression of stability factor in an analytic method. In this method, the landslide body needn't to be divided into many slices in order to calculate the result, thus, the calculation of the slice volume in most of existing models can be avoided, as a result, the calculation quantity can be greatly decreased, and the calculation precision can be improved a lot.(2) In this paper, the author introduces a method for fitting the sliding surface and the top surface of the landslide, so that the all-purpose model can be used in those complicated landslide bodies whose sliding surface and the top surface cannot be expressed by simple functions, therefore, our all-purpose model can greatly reflect the real condition of the landslide body, so that it is more valuable for real project.(3) According to the fitting process of the sliding surface and the analysis model, a computer program is designed and several typical example are computed with this program. Compared with the result of the geotechnical investigation and design on the spot, it is indicated that the calculation result of two-dimensional method in the design on the spot is so conservative that the design based on it is not only difficult to construct but also quite expensive, which always lead to unnecessary waste of both manpower and material resources. Therefore, it is obvious that the three-dimensional analysis method of landslide stability is more suitable for the real project.