孟村煤矿洛河组含水层垂向变化特征

Vertical change characteristics of Luohe Formation aquifer in Mengcun Coal Mine

孟村煤矿地处彬长矿区中西部,井田内白垩系洛河组厚度253.20~388.53 m,以往生产及研究过程中将巨厚洛河组含水层视为均质含水层,进行全段抽水试验,而忽略了洛河组含水层的垂向非均质性,从而造成抽水试验获取的水文地质参数与实际相差较大,进而影响到矿井涌水量的准确预测,造成矿井排水系统满足不了排水的要求。鉴于此,有必要从洛河组含水层的垂向上来研究其水文地质变化特征。通过将近年来井田洛河组含水层精细划分进行分层抽水试验、水质全分析测试及地质编录基础上研究发现,整体上洛河组砂岩含水层岩性在垂向上有一定的沉积韵律,显示出5段岩性的变化特征,在垂向上随着洛河组含水层埋深的增大,水位标高逐渐降低,矿化度逐渐升高,代表深循环滞留型的Na^(+)、SO_(4)^(2-)、Cl^(-)逐渐增加,代表浅循环的Ca^(2+)、HCO_(3)^(-)逐渐减小,钻孔的水温随埋深增大而增加;洛河组含水层中部富水性最强,上部次之,下部最弱。研究成果对孟村煤矿在巨厚含水层下安全采煤具有一定的指导意义。

Mengcun coal mine is located in the central and western part of Binchang mining area,and the thickness of Cretaceous Luohe Group in the mine is 253.20~388.53m.During the production and research process in the past,ultra-thick Luohe Group aquifer was regarded as a homogeneous aquifer,and pumping test was carried out in the whole section,but neglecting the vertical non-homogeneous characteristics of the aquifer in the Luohe Group,which resulted in the large difference between the hydrogeological parameters of the pumping test and the actual one,which affected the accurate prediction of water inflow of mine,resulting in the drainage system cannot meet the requirements.In view of this issue,it is necessary to study the hydrogeological characteristics of the Luhe Group aquifer from the vertical direction.In recent years,on the basis of the fine delineation and layered pumping test,water quality analysis test and geological cataloguing of Luohe Group aquifer in the mine,we have found that:on the whole,the lithology of Luohe Group sandstone aquifer has a certain depositional rhythm in the vertical direction,which shows the characteristics of the lithology change of 5 segments,and in the vertical direction,with the increase in the buried depth of the aquifer in the Luohu Group,the water elevation is gradually reduced,and the mineralisation gradually increases,the gradual increase of Na^(+),SO_(4)^(2-),and Cl^(-),representing the deep cycle retention-type,and the gradual decrease of Ca^(2+)and HCO_(3)^(-),which represent shallow-cycle retention type,and the water temperature of the boreholes increases with the depth of burial.The water-richness is strongest in the middle part of the aquifer of the Luohe Formation,followed by the upper part,and the weakest in the lower part.