Study on feasibility evaluation of continuous mining of residual coal based on variable weight fuzzy theory

In order to solve the problem that can only be qualitatively determined when the continuous machine is used in residual mining areas,based on the existing domestic short-wall continuous mining technology and continuous mining equipment, on the basis of fully considering the residual mining areas of mining and geological conditions, the exploration and analysis of the residual coal mining areas adopt the feasibility of the extraction of mathematics evaluation method and criteria.According to fuzzy mathematics, a comprehensive evaluation method of analytic hierarchy process and variable weight theory was proposed. The system analyzed the four aspects of geological structure conditions, coal seam occurrence, mining safety factors, and block irregular factors. A feasibility evaluation index system (19 factors) was constructed based on the characteristics of residual coal mining areas and continuous mining technology, and quantified each factor with reference to the domestic coal industry norms and standards or expert scoring method to obtain different indicators. In this way, the reasonable value ranges of different indicators were obtained, the indicator evaluation matrix was established and the initial weight of the indicators was determined. The initial weight was adjusted according to the actual situation, the weight of “poor” factor was increased, and the weight of “good” factor was reduced so as to make it more realistic. Finally, the contribution of the maximum evaluation index was taken into consideration,and the maximum membership degree was used as the evaluation criterion to determine the feasibility of continuous mining in residual coal area.The rationality and accuracy of the evaluation method were verified through three different case evaluations of Shengping Coal Mine, Zhangjiamao Coal Mine and Nanguan Coal Mine.The study shows that this method is an effective mathematical evaluation method for quantitatively determining the suitability of continuous mining technology in residual coal areas based on the feasibility influencing factors of residual coal areas proposed by the coal mine site, with reasonable weight given to indexes and appropriate calculation method, and it has important reference significance for small mines to make decisions on introducing continuous mining technology.