Application Of Fast Lagrangian Analysis For Continuum Based On Strength Reduction To Slope Engineering

The numerical method of analyzing slope stability is well-developed in the recent years, particularly, when the strength reduction method is combined with finite element method and finite difference method, as a result, numerical method could relate to traditional safety coefficient. However, the criterion of slope failure is not satisfied. Thus, the paper introduces a criterion of slope failure which is suitable for Flac-3d, otherwise, it obtains the slope critical slip surface by shear strain increment and velocity vector. While the method is proved to be rational and practical, it is applied to the slope stability analysis of Yeqi mountain II slope in WuZhou, and the failed slope is supported by frame beam with pretensioned cable. Finally the design parameter of pretensioned cable is optimized. The results are as followed:(1) Displacement mutation is proposed as one of the criterions of slope failure, otherwise, the convergence of algorithm is concerned. The criterion is definite in physical significance, distinct in definition, and easy to be practiced.(2) The critical slip surface is obtained according to the connectivity of shear strain increment and consistency of velocity vector.(3) The Fast Lagrangian difference method based on shear strength reduction is applied to analyze the stability of the slope which is taken for example. Sensitivity of the slope parameter is researched. The influence of four parameters to calculation accuracy is studied, the four parameters are: internal friction angle, cohesive strength, dilation angle, Young's modulus. The subsequence of the sensitivity to the slope of the four parameters are: internal friction angle, cohesive strength, dilation angle, Young's modulus.(4) The Fast Lagrangian difference method based on shear strength reduction is applied to the slope stability analysis of Yeqi mountain II slope in WuZhou. The results indicate that the slope is stable when it is in dry season, and it is instable in rainy season, support is necessary. Frame beam with pretensioned cable is employedto reinforce the slope, the result satisfies the design well. Finally, three parameters of the pretensioned cable is optimized, they are installation angle, length and the pretensioned force.