Mine water inflow modes and scientific design of drainage boreholes in roof confined aquifer of coal seam
-
摘要: 针对煤层顶板承压含水层涌水模式不清的问题,从煤层回采过程中顶板含水层涌水的时空变化特征入手,提出顶板含水层涌水量由静态储存量和动态补给量构成,认为静态储存量主要受来压步距、顶板垮落和导水裂隙(合称冒裂)影响区含水层厚度、含水层给水度控制,动态补给量主要受冒裂影响区外围含水层厚度、渗透性流场中水力梯度和过水断面面积控制;根据导水裂隙波及含水层情况,将顶板含水层涌水模式划分为井底进水的触及井涌水、井壁及井底进水的非完整井涌水和井壁进水的完整井涌水3种模式,并基于地下水渗流理论给出不同涌水模式下动态补给水量计算公式;针对以往疏放水钻孔数量多及疏放水量大的问题,以实现工作面顶板含水层静态储存量疏放后动态补给量可控为目的,提出冒裂区高度控制钻孔深度、单孔水位影响半径控制钻孔布置间距、钻孔疏放水量稳定时间控制超前疏放时间的疏放水钻孔优化设计理念,对疏放水及疏放钻孔布置进行优化,形成系统的顶板含水层水疏放体系。研究结果丰富了煤层顶板含水层涌水量计算和控制方法,对顶板水害防控具有实际的指导意义。Abstract: Aiming at the uncertainty of mine water inflow mode, this paper analyzes the spatiotemporal variation characteristics of mine water inflow at first, and get a conclusion that the mine water is composed of static storage and dynamic recharge. And the static storage is mainly affected by weighting interval, the aquifer thickness of caving and fracture zone height and specific yield; the dynamic recharge is mainly affected by caving and fracture zone height and specific yield, hydraulic gradient in permeable flow field and discharge section area. According to the spatial relationships between water conducted fissure and roof aquifer of coal seam, the mine water inflow mode is classified into 3 types: partially penetrating well with water entering from well bottom, partially penetrating well with water entering from well bottom and wall, and completely penetrating well with water entering from well wall. And then the different calculation formulas of dynamic recharge for three mine water inflow modes are given based on groundwater seepage theory. For the large quantity drainage boreholes and excess quantity drainage, the optimal design concept of drainage borehole is proposed, which consists of caving and fracture zone height controlling boreholes depth, influence radius of single hole controlling borehole layout, and stable time of drainage controlling advanced drainage time, so as to optimize the layout of drainage water and drainage borehole, and establish the system of drainage of roof aquifers. The results offer an alternative for the scientific connotation of calculus formula and control methods for mine roof water inflow, which has practical guiding significance for prevention and control of mine roof water disaster.
-
表 1 陕北某矿工作面顶板水疏放情况统计
Table 1 Statistics of roof water drainage of a mine working face in northern Shaanxi
工作面 钻孔数量 累计疏放水时间/月 累计疏放水量/万m3 31103 66 18.3 184.3 31104 55 18.5 201.6 31105 146 21.4 1 978.5 31107 57 21.9 367.5 31201 127 15.3 778.5 31202 73 17.6 590.0 31203 120 18.0 867.0 31401 146 25.5 706.2 平均 99 20.0 -
[1] 钱鸣高, 缪协兴, 许家林. 岩层控制的关键层理论[M]. 徐州: 中国矿业大学出版社, 2003.QIAN Minggao, MIU Xiexing, XU Jialin. The theory of key strata in ground control[M]. Xuzhou: China University of Mining and Technology Press, 2003. [2] 梁世伟. 薄基岩浅埋煤层顶板突水机理的研究[J]. 矿业安全与环保, 2013, 40(3): 21–24. https://www.cnki.com.cn/Article/CJFDTOTAL-ENER201303005.htmLIANG Shiwei. Research on roof water inrush mechanics of shallow coal seam with thin base rock[J]. Mining Safety & Environmental Protection, 2013, 40(3): 21–24. https://www.cnki.com.cn/Article/CJFDTOTAL-ENER201303005.htm [3] 刘东. 浅埋煤层顶板突水机理研究[D]. 西安: 西安科技大学, 2017.LIU Dong. Research on roof water inrush mechanics of shallow seam[D]. Xi'an: Xi'an University of Science and Technology, 2017. [4] 李超峰, 虎维岳. 回采工作面顶板复合含水层涌水量时空组成及过程预测方法[J]. 水文地质工程地质, 2018, 45(3): 1–13. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG201803001.htmLI Chaofeng, HU Weiyue. Prediction method of mine water inflow regime from a layered extra-thick aquifer[J]. Hydrogeology & Engineering Geology, 2018, 45(3): 1–13. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG201803001.htm [5] 虎维岳. 浅埋煤层回采中顶板含水层涌水量的时空动态预测技术[J]. 煤田地质与勘探, 2016, 44(5): 91–96. http://mdkt.cbpt.cnki.net/WKD/WebPublication/paperDigest.aspx?paperID=01bd9eb3-c4c2-4c5a-b1bb-7e5b76dfddc1HU Weiyue. Water inflows prediction technique of water inflow from roof aquifer during extraction of shallow seam[J]. Coal Geology & Exploration, 2016, 44(5): 91–96. http://mdkt.cbpt.cnki.net/WKD/WebPublication/paperDigest.aspx?paperID=01bd9eb3-c4c2-4c5a-b1bb-7e5b76dfddc1 [6] 刘洋, 张幼振. 浅埋煤层工作面涌水量预测方法研究[J]. 采矿与安全工程学报, 2010, 27(1): 116–120. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201001024.htmLIU Yang, ZHANG Youzhen. Forecast method for water inflow from working face in shallowly buried coal seam[J]. Journal of Mining & Safety Engineering, 2010, 27(1): 116–120. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201001024.htm [7] 陈酩知, 刘树才, 杨国勇. 矿井涌水量预测方法的发展[J]. 工程地球物理学报, 2009, 6(1): 68–72. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDQ200901016.htmCHEN Mingzhi, LIU Shucai, YANG Guoyong. The development of mining water inflow predict method[J]. Chinese Journal of Engineering Geophysics, 2009, 6(1): 68–72. https://www.cnki.com.cn/Article/CJFDTOTAL-GCDQ200901016.htm [8] 管恩太, 武强. 矿井涌水量预测评述[J]. 中州煤炭, 2005(1): 7–8. https://www.cnki.com.cn/Article/CJFDTOTAL-ZZMT200501004.htmGUAN Entai, WU Qiang. The review on predicting mine discharge[J]. Zhongzhou Coal, 2005(1): 7–8. https://www.cnki.com.cn/Article/CJFDTOTAL-ZZMT200501004.htm [9] 虎维岳, 闫丽. 对矿井涌水量预测问题的分析与思考[J]. 煤炭科学技术, 2016, 44(1): 13–18. https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201601003.htmHU Weiyue, YAN Li. Analysis and consideration on prediction problems of mine water inflow volume[J]. Coal Science & Technology, 2016, 44(1): 13–18. https://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201601003.htm [10] 黄欢. 锦界煤矿顶板水疏放技术优化研究[D]. 北京: 煤炭科学研究总院, 2017.HUANG Huan. Optimization research on dewatering technology of roof water in Jinjie mine[D]. Beijing: China Coal Research Institute, 2017. [11] 周振方, 靳德武, 虎维岳, 等. 煤矿工作面推采采空区涌水双指数动态衰减动力学研究[J]. 煤炭学报, 2018, 43(9): 2587–2594. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201809027.htmZHOU Zhenfang, JIN Dewu, HU Weiyue, et al. Double-exponential variation law of water-inflow from roof aquifer in goaf of working face with mining process[J]. Journal of China Coal Society, 2018, 43(9): 2587–2594. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201809027.htm [12] 赵宝峰. 煤层顶板砂岩含水层疏放水效果评价[J]. 矿业安全与环保, 2013, 40(6): 36–38. https://www.cnki.com.cn/Article/CJFDTOTAL-ENER201306012.htmZHAO Baofeng. Evaluation of drainage effect of roof sandstone aquifer of coal seam[J]. Mining Safety & Environmental Protection, 2013, 40(6): 36–38. https://www.cnki.com.cn/Article/CJFDTOTAL-ENER201306012.htm [13] 刘英锋, 郭小铭. 导水裂缝带部分波及顶板含水层条件下涌水量预测[J]. 煤田地质与勘探, 2016, 44(5): 97–101. http://mdkt.cbpt.cnki.net/WKD/WebPublication/paperDigest.aspx?paperID=d144ee55-944b-4117-9d58-5fde7608de22LIU Yingfeng, GUO Xiaoming. Prediction of water inflow in roof aquifer affected by water-flowing fracture zone[J]. Coal Geology & Exploration, 2016, 44(5): 97–101. http://mdkt.cbpt.cnki.net/WKD/WebPublication/paperDigest.aspx?paperID=d144ee55-944b-4117-9d58-5fde7608de22 [14] 薛禹群. 地下水动力学原理[M]. 北京: 地质出版社, 1986.XUE Yuqun. Groundwater dynamics[M]. Beijing: Geological Publishing House, 1986. [15] 吴吉春, 薛禹群. 地下水动力学[M]. 北京: 中国水利水电出版社, 2009.WU Jichun, XUE Yuqun. Groundwater dynamics[M]. Beijing: China Water & Power Press, 2009. [16] 覃意新. 门克庆煤矿顶板疏放水设计优化研究[J]. 建井技术, 2019, 40(5): 11–15. https://www.cnki.com.cn/Article/CJFDTOTAL-JJJS201905005.htmQIN Yixin. Optimized study on design of mine roof water drainage in Menkeqing mine[J]. Mine Construction Technology, 2019, 40(5): 11–15. https://www.cnki.com.cn/Article/CJFDTOTAL-JJJS201905005.htm [17] 赵春虎, 董书宁, 王皓, 等. 采煤工作面顶板含水层井下疏水钻孔涌水规律数值分析[J]. 煤炭学报, 2020, 45(增刊1): 405–414. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2020S1044.htmZHAO Chunhu, DONG Shuning, WANG Hao, et al. Analysis of water inrush from boreholes for drainage of confined aquifer by upward boreholes in underground coal mining face[J]. Journal of China Coal Society, 2020, 45(Sup. 1): 405–414. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2020S1044.htm