The Analysis And Prediction On Catastrophic Phenomenon In Mining Subsidence

With the development of coal industry, the effect of mining subsidence in coal mining is greater and greater, especially the abnormal conditions which do not accord with the general law of mining subsidence in mining subsidence.For example, the fall of overlying strata with large area in goaf etc, can be potential threats to underground production, and also threat the personal safety and mine production safety. Therefore, based on the catastrophe theory, the catastrophic phenomenon of mining subsidenceare are studied as flollows:Firstly, based on the study of theoretical research results on mining subsidence and related materials, the concept of mining subsidence mutation is put forward. Then, the characteristics of mining subsidence mutation are summarized, such as nonlinearity, discontinuity, abruptness etc. According to process characteristics and damage degree of overburden failure, the types of mining subsidence mutation are divided. Scendly, during the analysis on mutation factors which effected the mining subsidence, the geological and mining inducement are qualitatively and quantitatively studied separately. Using analytic hierarchy process as quantitative analysis, importance weight of influencing factors are calculated. Based on the analysis results above, according to the energy conservation principle and catastrophe theory, the mutation mechanical model of key stratum is established, and cusp catastrophe theory is used to study instability and mutation, according to establishment of key stratum potential function, the mechanism and necessary and sufficient conditions of mining subsidence mutation are revealed, then critical length formula of key stratum instability on working face is derived. Taking the similar material simulation experiment of Tongchuan mining bureau Yakou mine as example, based on the catastrophe model of key stratum, the experimental results are analyzed, and the results show better consistency. Then the feasibility and rationality of research method are verified. Finally, based on the characteristics mining subsidence mutation, influencing factors and occurrence mechanism, the preventive measures of mining subsidence mutation are put forward.