西湾露天煤矿剥采边帮涌水超前治理技术研究与应用

Research and application of advance treatment technology for water inrush from stripping side slope in Xiwan Open-pit Coal Mine

为有效治理露天煤矿剥采面临的边帮涌水水害问题,以西湾露天煤矿边帮涌水治理为工程背景,通过抽水试验法和瞬变电磁法确定风化基岩和烧变岩地层为受注地层;利用钻孔电视成像仪对治理地层裂隙发育情况进行了探查,根据裂隙发育特征和露天煤矿爆破剥采方式综合确定了帷幕墙设计参数和超前预注浆施工工艺。结果表明:超前注浆治理工程实施后,受注地层透水率降为1.95~6.11 Lu,对应渗透系数小于0.0001 cm/s,矿坑东侧抽排水量基本稳定在10884 m^(3)/d,治理范围内仅1处出水点较前期堵水阶段减水率达92.12%,说明超前预注浆治理技术构建帷幕墙能够大幅增加浆液留存率,可对裂隙进行有效充填,阻隔地下水在边帮涌出。

In order to effectively control the water inrush hazard at side slope faced by strip mining of open-pit coal mine,taking the side slope water inrush control of Xiwan Open-pit Coal Mine as the engineering background,the weathered bedrock and burnt rock strata are determined as the injectable strata by pumping test method and transient electromagnetic method;the borehole television imager was used to explore the fissures development condition in the strata,and the design parameters of the curtain wall and the advance pre-grouting construction technology were determined comprehensively according to the fissures development characteristics and the blasting stripping method of the open-pit coal mine.The results show that after the implementation of the advance grouting treatment project,the water permeability of the injected stratum is reduced to 1.95~6.11 Lu,and the corresponding permeability coefficient is less than 0.0001 cm/s,the drainage volume at the east side of the pit is basically stable at 10884 m^(3)/d,and there is only one water outlet within the control range,and the water reduction rate is 92.12%compared with the previous water plugging stage,indicating that the construction of curtain wall by the advance grouting treatment technology can significantly increase the slurry retention rate to effectively fill the cracks,and can prevent groundwater inrush at the side slope.