Research On Stability Of Non-coal Mine Peak Board Based On Fuzzy Comprehensive Evaluation Method

The roof collapse accident is a type of accident in which the frequency of non-coal mines is high and the number of casualties is high.Therefore,studying the stability factors of the roof and controlling the factors that have a great influence on the stability of the roof in advance are of great significance for controlling accidents and reducing casualties.significance.When carrying out underground mining operations,due to the fact that the ore body storage conditions cannot be ascertained in detail,there are many factors affecting the stability of the roof.In view of the different environmental factors of each non-coal underground mine,the factors affect the roof in different situations.The importance of stability impact is also different.We divide these influencing factors into five categories:spatial form factors,geological factors,hydrological factors,mechanical factors,and engineering environmental factors.In this paper,the Zhangjiawa iron ore mine of Luzhong Mining Co.,Ltd.is taken as the research background.The analytic hierarchy process is used to analyze the weight of each influencing factor,and the consistency test is passed.Finally,the weighting results of each influencing factor are obtained.The numerical simulation experiment selected the top plate of the 150m goaf in the buried depth as the research object,and constructed the FLAC~3DD numerical simulation model.The influence factors of roof stability were analyzed by changing the lithology combination of roof thickness,roof exposed area and rock tensile strength.In the analysis process,the maximum displacement of the roof and the plastic zone distribution of the roof are selected as the evaluation criteria,and the variation of the maximum displacement of the roof and the distribution of the plastic zone is obtained.Through numerical simulation test,it can be found that when the goaf is formed,the displacement of the central axis of the top plate and the bottom plate is more obvious than other areas,the displacement of the central axis of the top plate is the largest,and the displacement decreases as the two gangs approach,and the plastic zone is concentrated.In the middle of the roof,the position of the two gangs in the goaf.Through numerical simulation test and analysis,the importance of the thickness of the roof,the exposed area of the roof,and the influence of the tensile strength of the rock on the stability of the roof are successively reduced,which is consistent with the results obtained by the analytic hierarchy analysis.According to the analysis of the factors affecting the stability of the roof,the factors affecting the stability of the roof are selected,and the weights of the index of the index are evaluated.The factors affecting the stability of the roof are selected to establish the stability of the roof of Zhangjiawa Iron Mine.The evaluation system,the evaluation matrix of each factor is constructed,the fuzzy mathematical model of the roof stability evaluation is established,and then the fuzzy comprehensive evaluation of the roof of the 150m goaf of the Zhangjiawa iron ore mine of Luzhong Mining Co.,Ltd.is carried out to obtain the stability of the roof Comprehensive evaluation results.