The damage evaluation of mining subsidence of coal mining area based on fuzzy comprehensive evaluation: A case study in YuShenfu mining area

In this paper, Yushenfu mining area is taken as an example. On the basis of analysis and research of formation mechanism of mining subsidence, using principal component analysis and grey correlation analysis method, factors which affect the damage degree of mining subsidence have been selected. It is determined that disturbance coefficient, the ratio of width to depth, comprehensive hardness of overlying strata, subsidence coefficient and the ratio of mining depth and height are key influencial factors of damage degree of mining subsidence, and they are taken as evaluation indexes of damage evaluation later. Then, the fuzzy comprehensive evaluation is used to make quantitative evaluation of mining subsidence. The results show that: first, there are 9 mines whose damage degree of mining subsidence reached III (serious) among the 12 typical mines of YuShenFu mining area, and the other 3 belong to II (secondary), showing seriousness on the whole. The evaluation results correspond to the conclusion of qualitative judgment and actual situation; second, those mines which show serious mining subsidence all display that disturbance coefficient virtually is close to 1, the ratio of depth to thickness is close to or lower than 50, the ratio of width to depth is almost higher than 1, subsidence coefficient lies around 0.7 and the comprehensive hardness of overlying strata is medium hard. These not only fully reveals the main damage form of mining subsidence of YuShenFu mining area, that is, discontinuous cutting off type damage, but also truly reflects the coal-mining method (longwall mining), the roof management method (all collapse) as well as the traits of the overburden strata layer of coal measures. As a result, the consistency of evaluation results and evaluation indexes fully reflect the availability and scientificity of evaluation index system and the accuracy of evaluation method.