Longmenshan Orebody Mining Area L - 7 Goaf Stability Analysis Research

Growing demand for natural resources, especially mineral resources appeared with the development of the economy in our country. Resources to predatory development would inevitably lead to many problems, the goaf’s stability and security governance is one of them. This thesis takes the project of "goaf governance and mining method integrated technical research in the longmenshan mining area" for the research background, Combining with the engineering geology survey, CMS detection, indoor rock mechanics test, and using computer numerical simulation and variable fuzzy sets theory, the thesis makes stability analysis of the L-7ore bodies’goaf which is located in yueshan copper mines in anhui province. Results pave the way for monitoring the goaf’s stability and goaf governance. Chief research contents and conclusions of this thesis are as follows:Based on goaf field investigation, CMS detection and investigation of structural surface, The thesis collects basic information which is affecting the stability of rock engineering, analyzes the effection of goaf’s stability from rock joints fracture feature, the status of the goaf, hydrogeological situation, And finally summed up the four main reasons of the impact of L-7ore body goaf stability. Considering the actual conditions of mine, the preliminary evaluation of its stability is poorer.Through laboratory experiments, the thesis measures the basic physical-mechanical parameters of four kinds of samples in the mining areas. The stability of rock is evaluated by using RMR rock mass classification, Q system classification and BQ rock mass classification. Consequently, we can draw the conclusion that the overall rock quality is good and the surrounding rock is generally stable. On this basis, by means of the Hoek-Brown theory and the Roclab software, the thesis gets basic mechanical parameters of the rock after engineered analyzed, provides basic data for numerical simulation and fuzzy evaluation model.The thesis accurately establishs computation model according to actual ore body by achieving Numerical simulation coupling modeling between SURPAC and FLAC3D, The comprehensive analysis was summarized to stress, displacement, plastic zone and the safety degree of roof in FLAC3D. By analyzing simulation results, we can draw the conclusion that the overall stability of L-7ore body goaf is bad and there will have instability phenomena in regional field. Results agree very well with the states of the mining filed.The thesis summarizes and analyzes main factors of the influence on the stability of L-7ore body goafs, using the variable fuzzy sets theory to establish variable fuzzy comprehensive evaluation mode of the goaf surrounding rock stability, the model makes the leveled characteristic value as criterion. Analysis and evaluation is made on the three big goafs of A, B, E which influence global stability of the mining areas, therefore we can draw a conclusion that the stability level of goafs is poor stability. Aimed at evaluation results and according to actual conditions of goafs, the thesis provides initiative schemes to deal with the goafs.