| The water-inrush problem from coal floor has become a major security hidden danger of coal mining. Mining has become the main mining way of the deep coal resources development. To adjust to this, the limestone water prevention of coal floor seems to be important. Based on the key technology of limestone water prevention used on the 10 coal seam of Yuandian Mine No.101 and No.102, this paper made a variety of studies. Firstly, hydrogeological character of study areas was analysed. The sedimentary character, runoff character, pumping test and hydrochemical analysed results of limestone showed that water-bearing stratum of Taiyuan No.1～4 rock stayed in a relatively closed hydrogeology units, recycle was lightly weak, and aquifer ability was weak-medium, and the hydrogeological conditions were medium-complicated. Meanwhile, Gray BP artificial neural networks and numerical simulation were used to predict the coal-floor's destroyed depth under the mining impact. Both of these two predictions showed the close result and the maximum was 14.23m. Secondarily, the 10 coal seam water-resisting layer integrity of Mine No.101 and No.102 was studied by using the Fractal Theory. Then combining with the floor lithology, the water-resisting layer thickness and the rock combinations, it made the conclusion that the floor's water-resisting ability was relatively good. Obtained by numerical simulation showed that demarcated F2 fault between No.101 and No.102 under the mining influence were not activated, which indicated that water-inrush of fault cased a little threat to the study areas. But there might happen to be the abutment caused by 10 coal seam and Tai limestone coals as to cut by fault, which might happen to water-inrush. According to the study of study areas'geology and hydrogeological conditions and the study of karst collapse column formation conditions, it made the conclusions that there were no geological conditions for the study areas to form the larger karst collapse column. And according to the analyses of water-inrush coefficient theoretical calculation, it found the results that on the study areas'limestone aquifer layer, the water pressure was high, the floor water-resisting layers were thin, and confined water was in a "overrun mining" condition, there was possibility of limestone water-inrush. But according to the calculated results of the plate model theory, it showed that there was a very little possibility of floor water-inrush on -500m shallow side and -700m deep side when mining. By using the "Large Diameter Well Method" and Q-S method to budget the water inflow of study areas, it made conclusions that the normal water inflow was 244.17 m3/h and inrush water inflow water was 399.27 m3/h. Finally, by using grey fuzzy comprehensive evaluation method to evaluate the inrush water risk of 10 coal floor, and according to the evaluated results, it showed that water-inrush risk level of 10 coal floor on the study areas were mainly deal with water-inrush relatively safe areas and water-inrush threatened areas, which occupied 80 percents of the whole study area. The safe areas were just distributed in the southeast part of No.101 mining area that were mainly water-inrush relatively safe area; No.102 mining area was mainly water-inrush threatened area that was needed to be explored and prevented importantly during coal mining productive process. According to the hydrogeological conditions of study areas and combining with comprehensive evaluation analytical results together, this paper presented the concrete preventing water scheme and made a comprehensive exploration design of limestone water engineering to provide the experience for mining the next similar coal layer.Figure 33 table 31 reference [amount]... |
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