Evaluation Of Rock Burst Grade Based On Combinatorial Weighting And Butterfly Mutation Model

Rock burst is a common type of geological disaster in underground engineering construction,and its damage degree is relatively strong.Because of the sudden and unpredictable nature of rock burst,it is necessary to conduct in-depth research on different characteristics of underground engineering,and put forward a series of practical forecasting methods and preventive countermeasures.In this paper,a comprehensive evaluation model of rock burst grade is constructed by combining combinatorial weighting and abrupt progression model,and then the intensity of rock burst grade is predicted and explored.(1)This paper analyzes the influencing factors of rock burst from the three aspects of rock lithology,rock energy characteristics and surrounding rock stress,and selects four influencing factors as evaluation indexes.(2)The use of subjective and objective three methods(improved G1 method,coefficient of variation method and CRITIC method)combined with the combination of weighting method to improve the ranking of the importance of evaluation indicators,in order to eliminate the single use of some weighting method brought by the drawbacks.Then,the vertical distance method is used to improve the traditional TOPSIS method,and the weight of each rockburst identification index is allocated from different angles to achieve the purpose of improving the accuracy of calculation results.(3)Select the abrupt progression model corresponding to the number of evaluation indicators,and get the weight of each evaluation index through calculation.Based on this,carry out normalization calculation to get the value of abrupt progression,then divide the corresponding rock burst intensity grade interval,and obtain the final evaluation result through comparative analysis.Combined with the engineering example of Dongguashan deposit,the calculation and analysis are carried out according to the above method.Finally,the rock burst situation is predicted and the evaluation result of rock burst grade is obtained.The final evaluation results are in agreement with the real grade of rock burst,which verifies the feasibility of the comprehensive evaluation method based on combination weighting and butterfly mutation model in predicting the grade of rock burst intensity.