Fuzzy Measure Model Of Analysis For Rockmass Displacement Caused By Tunnelling Under Complex Topographic Conditions

Based on fuzziness of many kinds of influence factors for rock mass displacement and deformation, the fuzzy measure theory is applied to analyze rock mass displacement and deformation due to tunneling excavation in this paper. In accordance with the problems of rock mass displacement and deformation caused by tunneling excavation under complex mountainous topographic conditions, the original fuzzy measure model is improved and perfected, and the responsible formulation is deduced to analyze the problems of rock mass displacement and deformation, which is suitable for complex mountainous topographic conditions.The genetic programming approach is proposed to determine the parameter of fuzzy measure model, and the nonlinear symbol expression is obtained from many kinds of influence factors by using genetic programming method. The determined parameter is applied to predict and analyze rock mass displacement and deformation caused by tunneling excavation, and the parameter determined is in agreement with measured date, it is proved that genetic programming approach can be adopted to determine parameter of the fuzzy measure model, and the theoretical results can meet the accuracy requirements. In the process of calculation, Zhang Zhuo expressway Nantai No.three tunnel, Han Jia Zhuang tunnel and Belguim small spacing tunnel are selected as the analysis projections in this paper, the corresponding parameters determined by using genetic programming method are brought to fuzzy measure model. The theoretical results are consistent with the actual situation of the projects. It is proved that fuzzy measure method is suitable to analyze rock mass displacement caused by tunneling excavation under complex mountainous topographic conditions, and it is also applied to predict rock mass displacement caused by tunneling excavation under flat surface.In the process of research, compared with the results of the classical stochastic medium theory and the finite element method, the result indicates that the calculation results of the improved fuzzy measure model are consistent with the calculation results of other classical methods, thus the improved fuzzy measure model has good superiority to analyze the problems of rock mass displacement and deformation due to tunneling excavation under complex mountainous topographic conditions.