神府矿区大型水库旁烧变岩水保水开采技术研究

Study on water-preserved mining technology of burnt rock aquifer beside the large reservoir in Shenfu mining area

神府矿区是我国重要的煤炭生产基地和典型的高强度开采矿区,同时也是我国典型的干旱半干旱生态环境脆弱区,烧变岩水是区内的主要地下水资源之一。为研究区内烧变岩水对采煤的影响和烧变岩水的保护问题,以张家峁井田首采区首采地段5^(-2)煤开采为例,通过对水文地质结构系统和5^(-2)煤顶板导水裂隙带的分析,查明了研究区的水资源类型和特征,确立了5^(-2)煤保水开采对象,划分了5^(-2)煤保水开采分区,提出了烧变岩注浆帷幕截流保水开采新技术。研究结果表明:研究区的水资源类型主要有6类,其中仅有4^(-2)煤烧变岩水具有保水开采意义,5^(-2)煤开采划分为4^(-2)煤烧变岩水无水开采区和保水限采区。5^(-2)煤保水限采区设计的帷幕墙空间形态、帷幕线位置及数量、注浆钻孔排间距及结构合理,制定的钻探和注浆施工工序和工艺科学,实施的双位双向引流注浆、烧变岩全断面分区注浆、防渗截流效果即时检验等注浆帷幕关键技术可行。保水限采区5^(-2)煤工作面采前上覆4^(-2)煤烧变岩水预疏放和采后工作面涌水量实测结果表明,保水限采区内4^(-2)煤烧变岩水静储量约20 000 m^3,动态补给量不足5 m^3/h,注浆帷幕截流实现了帷幕内外4^(-2)煤烧变岩水的有效隔离,大幅减少了4^(-2)煤烧变岩水及与其有直接水力联系的常家沟水库水的排放,水资源保护性开采效果显著。

Shenfu mining area is a China’s important coal production base and a typical high intensity mining field,and also a typical fragile ecological environment of arid and semi-arid areas,in which the burnt rock aquifer is one of the main groundwater resources.In order to study the influence and the protection of the burnt rock aquifer,taking the 5 -2 coal mining in the first mining area of Zhangjiamao Mine field as an example,by studying the hydrogeological structure system and the water flowing fractured zone of 5 -2 coal roof,this paper investigates the types and characteristics of water resources,establishes the water-preserved mining target of 5 -2 coal seam,divides the water-preserved coal mining partition of 5 -2 coal seam,and puts forward a new water-preserved coal mining technology which is burnt rock grouting curtain interception method.The results show that there are six main types of water resources in the study area,where only the burnt rock aquifer of 4 -2 coal seam has the significance of water-preserved mining and the 5 -2 coal mining area is divided into anhydrous mining area and water-preserved limited mining area of the 4 -2 coal burnt rock aquifer.In the water-preserved limited mining area of 5 -2 coal seam,the designed curtain wall spatial morphology,the position and quantity of curtain line and the row spacing and structure of grouting drilling are reasonable.In addition,the procedure and processes of drilling and grouting planed are scientific,and the implemented key technologies of grouting curtain,such as dual-site bidirectional water diversion grouting,zoning grouting of burnt rock full section,immediate test of anti-seepage and interception effect,are feasible.The pre-drainage of the 4 -2 coal burnt rock aquifer of the working face before mining,and the measurement of the working face water inflow after mining in the water-preserved limited mining area of 5 -2 coal seam show that the static reserve and the dynamic recharge of the 4 -2 coal burnt rock aquifer water quantity are about 20 000 m 3 and less than 5 m 3 per hour respectively.It means the grouting curtain closure realizes the effective isolation of the 4 -2 coal burnt rock water inside and outside the curtain,and greatly reduces the water discharge of the 4 -2 coal-burnt rock water and the Changjiagou reservoir water with which it has direct hydraulic connection,and the protective mining effect of water resources is remarkable.