Rock Burst Rating Based On Improved Catastrophe Progression Method

Rock burst is a geological disaster often encountered in the excavation process of rock mass under high in-situ stress,which often brings incalculable losses to the construction personnel and equipment,so it is necessary to predict its occurrence and grade.In this paper,based on the catastrophe theory,the catastrophe series comprehensive evaluation method is used to predict the intensity grade of rock burst.(1)First of all,starting from the mechanism of rock burst,the surrounding stress,surrounding rock lithology,three aspects analysis the influence factors of rock burst,and the rock uniaxial compressive strength,the strength coefficient of stress ratio,stress,rock integrality coefficient and elastic deformation energy index as evaluation index to establish the comprehensive evaluation of rock burst intensity rating system.(2)Given that the mutation series method usually uses the expert scoring method to rank the importance of the index,which has a large subjectivity,this paper improves the ranking of the importance of the selected evaluation index from two perspectives(the combination weighting method of dispersion sum of squares and the TOPSIS theory approximation ideal solution ranking method).(3)According to the hierarchical structure of the five evaluation indexes to establish evaluation model,two kinds of mutation series of multi-dimensional indians huts mutation model,the conventional point dovetail mutation model,according to the importance sort normalized calculation,get the mutation level value,and dividing the corresponding rock burst intensity grade range,i.e.no(?)rock burst,the weak rock burst(?),medium(?)rock burst and strong rock burst(?).The optimal catastrophe progression model for rock burst prediction is obtained by means of sample data regression.Taking jiangbian hydropower station as an example,this paper selects 20 representative learning samples of cavern construction with relatively complete rock burst data,analyzes and calculates them according to the above methods,and finally predicts the rock burst conditions of the later three cavern sections,and obtains the rock burst grade evaluation results.The results are consistent with the actual rock burst situation of this working face,and verify the practicability and feasibility of the improved catastrophe series comprehensive evaluation method in the prediction of rock burst intensity grade.