基于GIS侏罗系3_-1煤层顶部砾石层隔水性评价

The Evaluation of the Water Resistance of the Gravel Layer at the Top of the Jurassic 3_-1 Coal Seam Based on GIS

摘要: 鄂尔多斯盆地煤炭资源丰富，侏罗系煤层开采过程中顶板砂岩水害威胁矿井安全生产，而煤层顶板上覆砾石层的隔水性能对于采掘过程防治水工程和顶板管理有着重要影响。本文以泊江海子矿二盘区3₋₁煤层顶部砾石层为对象，采用GIS信息与层次分析方法相融合，建立了多因素影响下的多层次煤层顶板砾石层隔水性预测模型，对开采前后影响砾石层隔水性的7个和9个指标进行评价分区。结果表明，3₋₁煤层开采会导致砾石层隔水性相对减弱，盘区西翼由采前大范围隔水性较强和中等区域变为隔水性弱和较弱区域，且范围向四周扩散增大；东翼隔水性强区和较强区范围大幅缩减，且部分区域减弱为隔水性中等区；中部所受影响较小，隔水性鲜有变化。为泊江海子3₋₁煤层和鄂尔多斯盆地北缘侏罗系煤层开采水害防治提供理论指导。

Abstract: The Ordos Basin is rich in coal resources. The roof sandstone water hazard in the Jurassic coal seam mining process threatens the safe production of the mine, and the water isolation performance of the overlying gravel layer on the coal seam roof has an important impact on the water prevention and control engineering and roof management in the mining process. In this paper, the gravel layer at the top of 3₋₁ coal seam in the second panel of Bojianghaizi coal mine is taken as the object, and the GIS information and the analytic hierarchy process are combined to establish a multi-level coal seam roof gravel layer under the influence of multiple factors. The prediction model evaluates and divides the 7 and 9 indicators that affect the water resistance of the gravel layer before and after mining. The results show that the mining of 3₋₁ coal seam will lead to the relative weakening of the water insulation of the gravel layer, and the west wing of the panel will change from a large range of strong and medium water insulation before mining to a weak and weaker water insulation area, and the range will expand to the surrounding area. The range of strong water-resisting area and stronger water-resisting area in the east wing is greatly reduced, and some areas are weakened to medium water-resisting area. The middle is less affected, and the water insulation is rarely changed. It provides theoretical guidance for the prevention and control of water disasters in Bojianghaizi 3₋₁ coal seam and Jurassic coal seam in the northern margin of Ordos Basin.