Comprehensive Evaluation Method Of Rock Burst Hazard For Coal Face Extraction

The working face safety affected by rock burst is becoming more and more serious,with the complication of mining conditions in China.How to effectively evaluate the rock burst hazard of mining area is becoming more and more important.At present,there are deficiencies in the evaluation methods,such as unreasonable selection of indicators and failure to consider differences weights of different indicators.In order to optimize the method for evaluating the rock burst hazard of excavation coal face,this paper has carried out a study on the evaluation method of rock burst hazard for working coal face based on the methods of engineering investigation,statistical analysis,fuzzy mathematics,computer programming and engineering practice.The rock burst hazard assessment model for working coal face is put forward,which provides basis for prevention and control rock burst in working coal face.The main conclusions of the paper are as follows:(1)By analyzing typical rock burst cases in different mining areas,the main influencing factors of rock burst hazard in working coal face are summed up.According to the frequency of rock burst occurring under the influence of various factors,the importance ranking of rock burst hazard in working coal face is given,and the example database of rock burst in working coal face is constructed.(2)The evaluation index of rock burst hazard in working coal face is selected,and the three-level evaluation index system for the rock burst hazard in working coal face is established.Namely:(1)target layer,Comprehensive evaluation method of rock burst harzed for coal face extraction,(2)criterion layer,geologic factor,mining factor,(3)index layer,7 geological factors for working coal face,the influence of roof,the uniaxial compressive strength of coal,the elastic energy index of coal,the structural development degree,the variation factors of coal thickness,and the occurrence history of rock burst.The mining condition of the protective layer,the influence of goaf,the width of coal pillar,the thickness of showings coal,the reasonable layout of working coal face,the width of working face and the overlying coal pillar 8 mining technology factors.(3)Based on the Analytic Hierarchy Process(AHP),the absolute weight of each index is calculated and the comprehensive index model of rock burst hazard assessment is constructed.(4)Based on VB programming language,the software for rock burst hazard assessment for working coal face is compiled,including the main functions of CAD mine drawing reading,rock burst hazard synthetic index calculation,rock burst hazard record,rock burst hazard inquiry and so on,and the software is tested,all functions can be executed normally,and when there are numerical input errors,can give error message hints.(5)The engineering application and the example verification of the rock burst hazard assessment model and software for working coal face are presented,which proves the accuracy and practicability of the evaluation model.