基于集对分析-可变模糊集耦合法的砂岩含水层富水性评价——以宁东矿区金家渠井田侏罗系直罗组含水层为例

Water-richness evaluation of sandstone aquifer based on set pair analysis-variable fuzzy set coupling method:A case from Jurassic Zhiluo formation of Jinjiaqu coal mine in Ningdong mining area

我国西北地区的侏罗系煤炭资源开采过程中面临顶板水害威胁,其危害程度与煤层上覆地层的水文地质结构有关,对煤层顶板含水层富水性进行合理有效的预测评价,有利于对顶板水害防治做出科学的决策,从而实现安全开采。以宁东矿区金家渠煤矿为例,基于岩性,选取了砂岩等效厚度,砂岩岩性系数,砂泥互层数3个评价因素,建立了岩性影响指数评价指标;基于构造,针对断层、褶皱,选取了断层交端点密度、断层规模密度、煤层倾角变异系数3个指标作为主采煤层上覆直接充水含水层-直罗组砂岩含水层富水性的评价指标。在此基础上,引入集对分析-可变模糊集耦合评价方法,构建了基于集对分析-可变模糊集耦合评价法的直罗组含水层富水评价模型。利用“联系度”实现了富水评价指标与评价等级间的反映联系,利用“相对隶属度函数”实现了富水评价指标值之间的有机融合。在富水性相对分区的基础上,以研究区钻孔抽(放)水试验的单位涌水量为基准,综合确定了研究区富水性分区,结果表明,研究区整体富水性较弱,具有中等、弱2个等级分区,其中富水性中等区域主要位于研究区中北部,富水性弱区主要位于南部、东部及西部。

During the exploitation of Jurassic coal resources in Northwest China,many water inrush disasters,which are related to the hydrogeological structure of the overlying strata of coal seam,threaten the safe mining.The effective prediction and evaluation of water richness of the coal seam roof aquifer is conducive to making scientific decisions on the prevention of water disaster and realizing the safe mining of coal seam.A case of evaluation of water-richness of the sandstone aquifer in the Jurassic Zhiluo Formation overlying the main coal seam from Jinjiaqu coal mine in Ningdong mining area was studied.Based on the aquifer lithology,three evaluation factors,including the equivalent thickness of sandstone,the lithological coefficient of sandstone and the numbers of exchange layers between sandstones and mudstones,were selected to establish the lithological index.Based on the faults and folds structure,three factors including fault frequency density,fault scale density and the variation coefficient of the slop of the coal seam were selected as the evaluation index.Set pair analysis-variable fuzzy set coupling method was applied to establish the water-richness evaluation model and reveal the water abundance zones.The degree of connection was used to realize the connections between the water richness evaluation index and the evaluation grades,and the relative membership function was used to realize the integration among the evaluation index values.On the basis of relative zonation,the water yield evaluation zones in the study area was determined by referring the actual yields measured from borehole pumping tests.The prediction results show that the water abundance of Zhiluo formation can be divided into low and medium water abundance classes.The medium water richness areas were mainly distributed in the middle and north of the study area,while the low class of that were distributed in the south,east and west of the study area.