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综放开采条件下煤层顶板涌(突)水危险性评价

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  摘 要:为评价综放开采条件下煤层顶板涌(突)水危险性,以焦坪矿区某井田为例,通过水质分析和导水裂隙带發育高度分析相结合的方法,对矿井顶板涌(突)水水源进行了判定,同时在基于GI-变异系数法的含水层富水性分析,基于砂泥岩分布图的离层发育危险性分析和基于裂采比的冒裂安全性分析的基础上,通过叠加分析对顶板涌(突)水危险性进行了评价。结果表明:矿井顶板涌(突)水水源为白垩系下统洛河组下段砂岩裂隙潜水含水层水,以及发育在宜君组粗砾岩与直罗组顶部泥岩之间离层空间内的离层水。顶板涌(突)水危险的区域主要分布在井田中部和西部,其中中部的一、二盘区由于煤层采厚较大,导水裂隙带突破洛河组底界的范围较广,顶板涌(突)水危险性最大,且存在局部离层强突水区;井田西部三、四盘区主要为顶板涌(突)水中等危险区;井田东北部五盘区,大部分区域为相对安全区,局部存在含水层突水中等危险区。
  关键词:地质资源与地质工程;顶板水害;叠加分析;GI-变异系数法;突水危险性评价
  中图分类号:TD 163 文献标志码:A
  DOI:10.13800/j.cnki.xakjdxxb.2019.0310 文章编号:1672-9315(2019)03-0452-09
  Abstract:In order to evaluate the risk assessment of water inflow (inrush) from coal seam roof under fully mechanized caving mining, a mine field in Shaanxi Jiaoping mining area was taken as an example,the water source of the mine roof surge is determined by the method of water quality analysis and the development height analysis of the water conducting fracture zone.At the same time, on the basis of the water rich analysis based on the GI-variation coefficient method risk analysis of the separation development based on the sand shale distribution map,and safety analysis of fissure mining ratio,the risk of roof water inrush is evaluated by superposition analysis.The results indicate that the water source of the mine roof is the water in the lower section of the lower Cretaceous Luohe formation sandstone fissure dive aquifer,and the separated layer water developed in the separation space between the coarse conglomerate and the mudstone of the diojun group.The area of the roof inflow(inrush)water is mainly distributed in the middle and west of the well field.In the first and second panel of the middle part,the coal seam has a great thickness,and the water guide belt breaks through the wide range of the bottom of the Luohe group,so the risk of water inflow(inrush)from coal seam roof is the biggest.In addition,there is a local strong outburst area of abscission layer of water.The third or fourth panel of the west part is mainly dangerous areas.Most of the fifth panel in the northeast part of the mine area are relative safety areas,and the other is the middle dangerous area of abscission layer of water inrush.Key words:geological resources and geological engineering;roof water hazard;superposition analysis;GI-variation coefficient method;risk assessment of water inrush
  0 引 言厚煤层综放开采条件下,顶板覆岩破坏强烈,如果对顶板含水层分布及发育特征认识不足,往往会造成严重的顶板水害事故和水资源渗漏[1-6]。由于顶板突水事故水源多样,征兆不明显,突水量大,危害严重,因此,有效地评价煤层顶板水害危险性,针对性地圈定顶板突水危险区,对煤矿顶板水害预测及防治具有十分重要的指导意义。在顶板水害预测方面,不少学者采用数值模拟计算和统计分析等方法,研究和量化目标含水层富水性、导水裂隙带高度以及地下水渗流特征等矿井突水因素。武强等提出了基于AHP的“三图-双预测”方法,并借助三维数值模型,从顶板冒裂程度和含水层富水性2个方面对煤层顶板含水层突水危险性进行了评价[7-11]。李坤、张小明、杜伟升等在“三图”理论分析的基础上,建立了基于GIS与AHP综合分析法的煤层顶底板致灾含水层富水性指数模型[12-14]。任晓波等对传统的“三图-双预测法”进行了改进和修正,并在具体的矿井顶板涌(突)水危险性评价中,取得了较好的应用效果[15]。范立民等研究了突水溃砂机理,并采用基于GIS的多信息融合方法,对陕北神府矿区突水溃沙危险性进行了综合分区[16]。王生全等运用层次分析法,对青龙寺煤矿5-2煤层顶板含水层突水危险性进行了评价[17]。贺晓浪等采用层次分析、模糊聚类等方法,提出了陕北毛乌素沙漠区潜水含水层富水性评价模型[18]。   马雄德等将煤层赋存特征和开采条件作为顶板突水危险性分区评价的2大因素[19]。代革联等从頂板砂岩物质组成、孔隙特征、渗流特征、富水性等方面对顶板含水层涌(突)水危险性进行评价[20]。张海荣等在缺少煤层顶板水文地质信息且无法判明突水规律的情况下,尝试采用GIS复合分析的方法对煤层顶板水害进行评价预测,并取得了良好的实际应用效果[21]。以上不同学者从不同角度研究了煤层顶板突水危险性的评价预测方法。笔者在前人研究成果的基础上,以陕西焦坪矿区某井田为例,在分析水文地质特征的基础上,对顶板水害致灾水源进行了判定,从含水层富水性、离层发育危险性和冒裂安全性3个方面进行综合分析,对煤层顶板涌(突)水危险性进行了分区评价,为煤矿顶板水害防治提供理论支持。
  1 水文地质特征井田位于陕西焦坪矿区南部,矿井主采4-2号煤层,厚度0~31.53 m.煤层顶板主要含水层自下而上分别为侏罗系中下统直罗-延安组砂岩裂隙含水层、白垩系下统洛河组下段砂岩裂隙潜水含水层、白垩系下统洛河组上段砂岩裂隙潜水含水层、白垩系下统华池-环河组砂岩裂隙潜水含水层、第四系含泥质砂卵石潜水含水层。井田东部一盘区4-2煤层平均采厚约12 m,综采采煤工艺,全部垮落法管理顶板。在一盘区中部1412,1418工作面回采时,水害事故频发,共发生过9次突水(表1),顶板水害已经严重威胁了矿井的安全生产。
  1)突水量大,周期短。2010年12月至2013年5月发生过9次顶板突水突事故,最大矿井涌水量249~2 000 m3/h,涌水量较大。每次突水的时间间隔一般为60 d;
  2)突水水源稳定。根据井下突水点所取水样的水质检测结果,致灾水源为洛河组下段砂岩裂隙潜水含水层和直罗-延安组砂岩裂隙潜水含水层;
  3)突水点位置较为集中。1412,1418两工作面9次突水点的位置较为集中,距离间隔一般为160 m.综上分析可知,矿井突水量大小、突水次数、突水水源稳定性和突水点位置分布等,均具有典型离层突水的特点。
  2 矿井涌(突)水水源为了更加准确的判别顶板水害致灾水源,笔者从水质化验结果和导水裂隙带发育高度2个方面分别进行分析。2.1 水质分析1412,1418工作面发生突水后,为了更好的判别水源,工作人员在工作面突水点和采空区共采集了水样5份,对水中的K++Na+,Ga2+,Mg2+,Cl-,SO2-4,HCO-3,TDS等7个指标进行了化验分析,化验结果见表2.根据井下采集水样的水质化验结果,绘制水质Piper三线图(图1),根据主要阴阳离子分布位置的差异,可以直观的反映出各水样点水化学类型的差异。
  2.2 导水裂隙带通过上述水质分析结果,可以明确的判定出顶板突水的水源稳定,为上部砂岩裂隙含水层水。为了更加准确具体的判别致灾水源的层位,要对导水裂隙带的发育高度进行分析。根据文献[22-23]中的计算机数值模拟结果和矿方实际的探测资料,导水裂隙带高度与煤层采厚的比值约为19.5,导通至白垩系下统洛河组下段砂岩裂隙潜水含水层。由此可知,矿井致灾含水层为侏罗系中下统直罗-延安组砂岩裂隙潜水含水层和白垩系下统洛河组下段砂岩裂隙潜水含水层。由于前者直罗-延安组含水层厚度相对较小,富水性较弱,水量有限,对矿井涌水量的影响不大。而后者洛河砂岩潜水含水层为河流相沉积,富水性好,存在局部富水区,且以净储量为主,是矿井突水的主要充水水源。通过上述水质分析和导水裂隙带导通层位的分析结果可知,矿井突水水源稳定,主要来自白垩系下统洛河组下段砂岩裂隙潜水含水层。3 涌(突)水危险性评价充水水源和充水通道是煤矿顶板涌(突)水的2大必要条件。由前述分析可知,充水水源主要是白垩系下统洛河组下段砂岩裂隙潜水含水层,同时,根据一盘区工作面突水特征分析结果和文献[22-23]的研究成果,该矿井还存在明显的离层突水特征。能够引起矿井较大涌水,甚至导致离层水害事故的可致灾离层空间主要发育在宜君组粗砾岩和下位直罗组顶部泥岩之间(图2)。对于充水通道,该矿井地质构造相对简单,未发现大型的导水构造,因此可以判定采动引起的导水裂隙带是煤层顶板涌(突)水的主要充水通道。文中通过对洛河组下段砂岩裂隙含水层富水性、离层发育危险性、冒裂安全性分别进行评价分区,并将3个分区结果进行叠加分析,对顶板涌(突)水危险性进行综合性评价。
  3.1 主控因素富水性文中选取洛河组下段砂岩裂隙潜水含水层的厚度、岩芯采取率、冲洗液漏失量、单位涌水量和渗透系数5个主控因素,根据井田勘探时期钻孔数据,分别做出专题图。采用G1-变异系数法对各主控因素进行赋权,构建评价目标含水层富水性大小的综合指数,即富水性指数,然后进行综合性评价分区。3.1.1 主控因素的建立
  1)含水层厚度。通常情况下,若其它因素一定,含水层越厚,则含水量越大,富水性就越好。根据井田内洛河组下段砂岩裂隙含水层厚度统计数据绘制出含水层厚度等值线图(图3(a));
  2)岩芯采取率。通常情况下,岩芯采取率越低,说明岩层较为破碎,裂隙较发育,储水能力和导水能力越好,富水性越强。根据岩芯采取率绘制等值线图(图3(b));
  3)冲洗液漏失量。一般情况下,冲洗液漏失量越大,说明岩层的孔隙性越好,富水性越强。根据冲洗液漏失量绘制等值线图(图3(c));
  4)单位涌水量。是直观反映含水层富水性的重要参数,单位涌水量越大,含水层富水性及其与其他含水层的相互补给关系就越好。根据井田内水文钻孔的抽水实验结果,绘制等值线图(图3(d));
  5)渗透系数。是反映岩土体渗透能力的重要参数。渗透系数越大,说明岩土体的渗透能力越强,富水性也越强。根据井田内水文钻孔的抽水试验结果,绘制等值线图(图3(e))。
  3.1.2 权重确定
  4 结 论
  1)采用水质分析与导水裂隙带发育高度分析相结合的方法,判定煤层顶板涌(突)水的主要致灾水源为白垩系下统洛河组下段砂岩裂隙潜水含水层。煤层顶板可致灾离层空间发育在宜君组粗砾岩和直罗组顶部泥岩之间。   2)通过含水层富水性分区图、离层发育危险性分区图和顶板冒裂安全性分区图的复合叠加分析结果,矿井涌(突)水危险区主要分布在井田中部和西部,其中,中部一、二盘区矿井涌(突)水危险性最大,且存在局部强离层突水区。井田东北部和西南部矿井涌(突)水危险性小,大部分为相对安全区。
  参考文献(References):
  [1] 武 强,崔芳鹏,赵苏启,等.矿井水害类型划分及主要特征分析[J].煤炭学报,2013,38(4):561-565.WU Qiang,CUI Fang-peng,ZHAO Su-qi,et al.Type classification and main characteristics of mine water disasters[J].Journal of China Coal Society,2013,38(4):561-565.
  [2]王双明,黄庆享,范立民,等.生态脆弱矿区含(隔)水层特征及保水开采分区研究[J].煤炭学报,2010,35(1):8-14.WANG Shuang-ming,HUANG Qing-xiang,FAN Li-mini,et al.Study on overburden aquclude and water protection mining regionazation in the ecological fragile mining area[J].Journal of China Coal Society,2010,35(1):8-14.
  [3]范立民,马雄德,冀瑞君.西部生态脆弱矿区保水采煤研究与实践进展[J].煤炭学报,2015,40(8):1711-1717.FAN Li-min,MA Xiong-de,JI Rui-jun.Progress in engineering practice of water-preserved coal mining in western eco-environment frangible area[J].Journal of China Coal Society,2015,40(8):1711-1717.
  [4]范立民.保水采煤的科学内涵[J].煤炭学报,2017,42(1):27-35.FAN Li-min.Scientific connotation of water-preserved mining[J].Journal of China Coal Society,2017,42(1):27-35.
  [5]FAN Li-min,MA Xiong-de.A review on investigation of water-preserved coal mining in western China[J]. International Journal of Coal Science & Technology,2018,5(4):411-416.
  [6]柳 宁,赵晓光,解海军,等. 榆神府地区煤炭开采对地下水资源的影响[J].西安科技大学学报,2019,39 (1):71-78.LIU Ning,ZHAO Xiao-guang,XIE Hai-jun,et al. Influence of coal mining on groundwater resources in Yushenfu Area[J].Journal of Xi’an University of Science and Technology,2019,39(1):71-78.
  [7]武 强,黄晓玲,董东林,等.评价煤层顶板涌(突)水条件的“三图-双预测法”[J].煤炭学报,2000,25(1):60-65.WU Qiang,HUANG Xiao-ling,DONG Dong-lin,et al.“Three maps-two predictions” method to evaluate water bursting coditions on roof coal[J].Journal of China Coal Society,2000,25(1):60-65.
  [8]武 強,许 珂,张 维.再论煤层顶板涌(突)水危险性预测评价的“三图-双预测法”[J].煤炭学报,2016,41(6):1341-1347.WU Qiang,XU Ke,ZHANG Wei.Further research on “three maps-two predictions”method for prediction on coal seam roof water bursting risk[J].Journal of China Coal Society,2016,41(6):1341-1347.
  [9]Wu Q,Fan S K,Zhou W F,et al.Application of the analytic hierarchy process to assessment of water inrush:A case study for the No.17 coal seam in the sanhejian coal mine,China[J].Mine Water and the Environment,2013,32(3):229-238.
  [10]Wu Q,Liu Y Z,Zhou W F,et al.Assessment of water inrush vulnerability from overlying aquifer using GIS-AHP-based “three maps-two predictions” method:a case study in Hulusu coal mine,China[J].Quarterly Journal of Engineering Geology and Hydrogeology,2015,48(3-4):234-243.   [11]Wu Q,Liu Y Z,Zhou W F,et al.Evaluation of water inrush vulnerability from aquifers overlying coal seams in the menkeqing coal mine,China[J].Mine Water and the environment,2015,34(3):258-269.
  [12]李 坤,曾一凡,尚彦军,等.基于GIS的“三图-双预测法”的应用[J].煤田地质与勘探,2015,43(2):58-62.LI Kun,ZENG Yi-fan,SHANG Yan-jun,et al.The application of “three maps-two predictions” method based on GIS[J].Coal Geology & Eeploration,2015,43(2):58-62.
  [13]张小明,武强,刘红艳,等.集贤井田煤层顶板危险性综合评价与防治对策研究[J].煤炭工程,2016,48(S2):56-59.ZHANG Xiao-ming,WU Qiang,LIU Hong-yan,et al.Comprehensive evaluation for water hazard risk in coal seam roof of Jixian Mining Field and the preventive countermeasures[J].Coal Eegineering,2016,48(S2):56-59.
  [14]DU Wei-sheng,JIANG Yao-dong,MA Zhen-qian,et al.Assessment of water inrush and factor sensitivity analysis in an amalgamated coal mine in China[J].Arabian Journal of Geosciences,2017,10(21).
  [15]任晓波,吴瑞芳.基于煤层顶板充水含水层水压的“修正三图-双预测法”研究[J].煤炭工程,2016,48(S2):131-133.REN Xiao-bo,WU Rui-fang.A modified three graphics-two predictions method based on hydraulic pressure of aquifers above coal seam roof[J].Coal Engineering,2016,48(S2):131-133.
  [16]范立民,马雄德,蒋 辉,等.西部生态脆弱矿区矿井突水溃沙危险性分区[J].煤炭学报,2016,41(3):531-536.FAN Li-min,MA Xiong-de,JIANG Hui,et al.Risk evaluation on water and sand inrush in ecologically fragile coal mine[J].Journal of China Coal Society,2016,41(3):531-536.
  [17]王生全,武 超,彭 涛,等. 青龙寺煤矿5-2煤层顶板含水层突水危险性评价[J].西安科技大学学报,2018,38(6):959-965.WANG Sheng-quan,WU Chao,PENG Tao,et al.Evaluation of water inrush hazard in roof aquifer of 5-2 coal seam in Qinglongsi coal mine[J].Journal of Xi’an University of Science and Technology,2018,38(6):959-965.
  [18]賀晓浪,段中会,苗霖田,等. 陕北毛乌素沙漠区潜水含水层富水性及动态变化特征[J].西安科技大学学报,2019,39(1):88-95.HE Xiao-lang,DUAN Zhong-hui,MIAO Lin-tian,et al.Unconfined aquifer water-richness and dynamic change features of Mu Us Desert Area in northern Shaanxi[J].Journal of Xi’an University of Science and Technology,2019,39(1):88-95.
  [19]马雄德,范立民,贺卫中,等.浅埋煤层高强度开采突水危险性分区评价[J].中国煤炭,2015,41(10):33-36.MA Xiong-de,FAN Li-min,HE Wei-zhong,et al.Zoning and evaluation on water inrush risk in shallow coal seam with high intensity mining[J].China Coal,2015,41(10):33-36.
  [20]代革联,薛小渊,牛 超.基于水化学特征分析的象山矿井突水水源判别[J].西安科技大学学报,2017,37(2):213-218.DAI Ge-lian,XU Xiao-yuan,NIU Chao.Discrimination of water inrush source in Xiangshan coal mine based on chemical characteristics of groundwater[J].Journal of Xi’an University of Science and Technology,2017,37(2):213-218.   [21]张海荣,周荣福,郭达志,等.基于GIS复合分析的煤矿顶板水害预测研究[J].中国矿业大学学报,2005,34(1):112-116.ZHANG Hai-rong,ZHOU Rong-fu,GUO Da-zhi,et al.Investigation on predicting roof water gush in coal mines based on multi-factor analysis[J].Journal of China University of Mining & Technology,2005,34(1):112-116.
  [22]孙 魁.煤矿水害致灾机理研究[D].西安:西安科技大学,2016.SUN Kui.Study on disaster-causing mechanism of coal mine flood[D].Xi’an:Xi’an University of Science and Technology,2016.
  [23]孙 魁,王 英,李 成,等.巨厚煤层顶板离层水致灾机理研究[J].河南理工大学学报(自然科学版),2018,37(2):14-21.SUN Kui,WANG Ying,LI Cheng,et al.Mechanism of roof separation water disaster in thick coal seam[J].Journal of Henan Polytechnic University(Natural Science),2018,37(2):14-21.
  [24]许 武,夏玉成,杜荣军,等.导水裂隙带预计经验公式的“三性”探究[J].矿业研究与开发,2013,33(6):63-67.XU Wu,XIA Yu-cheng,DU Rong-jun,et al.Study on three properties of the empirical formula for estimating the height of water-flowing fractured zone[J].Mining R & D,2013,33(6):63-67.
  [25]方 刚,靳德武.铜川玉华煤矿顶板離层水突水机理与防治[J].煤田地质与勘探,2016,44(3):57-64.FANG Gang,JIN De-wu.Research on the roof stratifugic water inrush mechanism and control in Tongchuan Yuhua coal mine[J].Coal Geology & Exploration,2016,44(3):57-64.
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