Yunnan An Open Rock Slope Structure Parameter Optimization Study

The rock mass is the engineering material and engineering structure of slop of opencast mining which is the large-scale rock engineering formed by mining operations. Its stability is the prerequisite for normal production of mining. After excavation, there will be damage and artificial slop is formed and the stress of the original rock mass is redistributed, which will lead to instability and damage of slope to some extent. So, during the opencast mining, it is particularly important to select the reasonable parameters slope.The traditional optimization method for parameters of surrounding rock is setting value analysis such as the limit equilibrium method. In fact, the uncertainty of slope engineering not only includes fuzziness, also includes randomness. So the traditional analysis methods can not properly solve the fuzzy random uncertainty problem of slope engineering.Based on the present situation, mining plans with seven different parameters for a opencast mining stope design in Yunnan was firstly calculated and analyzed with the limit equilibrium method in this paper. With slope safety coefficient as evaluation indexes, it is concluded that e safety coefficient of plan 4,5 and 7 is less than allowable value of opencast mining slope.The fuzzy mathematics theory is adopted and the comprehensive fuzzy evaluation model is established considering safety and economic benefits. As for the uncertainty of slope engineering.0-1 is used to describe the transition from 'Yse' to 'No'. Four factors are selected and membership function between the quantitative and qualitative effect factors is established. After analysis, the width of 12.5 m for platform and the stope of 65°for slope are determined for the optimal slope geometric conditions parameters of slope.The stability of the stope was verified and analyzed with the numerical simulation method. Changes of displacement and stress, and the safety coefficient after slope mining are studied with fast Lagrange finite difference which is based on Strength reduction. The results show that slope is a stable state in overall during the excavation and unloading and there will be signs of local sliding. The conclusion agrees with actual situation.The results can be applied to the study of similar mining slope, and have a certain reference value.