隐伏断层作用下深厚覆盖层三维渗流分析
|
摘要
针对柴达木盆地深厚覆盖层及较大隐伏断层等不利地质条件严重影响坝基渗透稳定及大坝蓄水功能的问题,采用防渗墙来减少渗流量,并应用有限单元法对隐伏断层渗流特性、防渗措施及防渗墙渗控效果进行了分析。研究表明:哇沿水库采用70 m深悬挂式防渗墙可满足渗透稳定和大坝蓄水要求;若断层渗透系数较大,防渗墙需穿过透水断层,深入密实岩体内,插入深度需结合渗流量及岩体密实程度来综合确定;或对渗透系数较大的断层进行灌浆,减小其渗透系数,结合悬挂式防渗墙,减少渗流量;上述两种措施中防渗墙要避免将底端置于渗透性差异大的两种材料交界面处,以避免较大的防渗墙底部水力坡降导致的局部冲蚀,保证工程安全稳定的运行。研究成果可为柴达木盆地类似地质条件建坝提供技术支持和指导。
Unfavorable geological conditions such as deep overburden layers and large hidden faults in the Qaidam basin severely affect the seepage stability of the foundation and storage function of a dam. This study examines the cutoff wall measure for reducing seepage flow in a deep overburden layer with hidden faults, and uses a finite element method to analyze the seepage characteristics of this anti-seepage measure and its seepage control effect. Results show that adopting a suspended cutoff wall of 70 m deep, the Wayan reservoir meets the needs of seepage stability and water storage. If the seepage coefficient of a fault is large, the cutoff wall needs to pass through the fault and go deep into the dense rock mass, and its depth into the fault should be determined by combining the seepage flow rate and rock mass compactness. Also, we can decrease the permeability and seepage flow through grouting. For either of these two measures, the cutoff wall should avoid being extended into an interface of two materials widely different in permeability to prevent local erosion under the large hydraulic gradient around its tip, and its safe and stable operation must be ensured.
Unfavorable geological conditions such as deep overburden layers and large hidden faults in the Qaidam basin severely affect the seepage stability of the foundation and storage function of a dam. This study examines the cutoff wall measure for reducing seepage flow in a deep overburden layer with hidden faults, and uses a finite element method to analyze the seepage characteristics of this anti-seepage measure and its seepage control effect. Results show that adopting a suspended cutoff wall of 70 m deep, the Wayan reservoir meets the needs of seepage stability and water storage. If the seepage coefficient of a fault is large, the cutoff wall needs to pass through the fault and go deep into the dense rock mass, and its depth into the fault should be determined by combining the seepage flow rate and rock mass compactness. Also, we can decrease the permeability and seepage flow through grouting. For either of these two measures, the cutoff wall should avoid being extended into an interface of two materials widely different in permeability to prevent local erosion under the large hydraulic gradient around its tip, and its safe and stable operation must be ensured.
引文
[1]罗守成.对深厚覆盖层地质问题的认识[J].水力发电,1995(4):21-24.LUO Shoucheng.Understanding of geological problems of deep overburden layers[J].Water Power,1995(4):21-24.(in Chinese)
[2]党林才,刘荣丽,王仁坤,等.利用覆盖层建坝的实践与发展[M].北京:中国水利水电出版社,2009.DANG Lincai,LIU Rongli,WANG Renkun,et al.Practice and development of using overburden layers to build dams[M].Beijing:China Water&Power Press,2009.(in Chinese)
[3]高钟璞.大坝基础防渗墙[M].北京:中国电力出版社,2000.GAO Zhongpu.Cutoff wall in dam foundation[M].Beijing:China Electric Power Press,2000.(in Chinese)
[4]沈振中,邱莉婷,周华雷.深厚覆盖层上土石坝防渗技术研究进展[J].水利水电科技进展,2015,35(5):27-35.SHEN Zhenzhong,QIU Liting,ZHOU Hualei.Review of seepage control of earth-rockfill dams on thick overburden layer[J].China Rural Water and Hydropower,2015,35(5):27-35.(in Chinese)
[5]Xi N N,Tong F G,Liu G,et al.Finite element analysis of dam foundation seepage effect on cutoff wall depth of Guxue Concrete Gravity Dam[J].Advanced Materials Research,2014,1073-1076:1729-1732.
[6]白勇,柴军瑞,曹境英,等.深厚覆盖层地基渗流场数值分析[J].岩土力学,2008,29(S1):94-98.BAI Yong,CHAI Junrui,CAO Jingying,et al.Numerical analysis of seepage field in deep overburden foundation[J].Rock and Soil Mechanics,2008,29(S1):94-98.(in Chinese)
[7]宗敦峰,刘建发,肖恩尚,等.水工建筑物防渗墙技术60年Ⅰ:成墙技术和工艺[J].水利学报,2016,47(3):455-462.ZONG Dunfeng,LIU Jianfa,XIAO Enshang,et al.60years’perspective of the diaphragm wall technology for seepage control,Part I:construction method and workmanship[J].Journal of Hydraulic Engineering,2016,47(3):455-462.(in Chinese)
[8]宗敦峰,刘建发,肖恩尚,等.水工建筑物防渗墙技术60年Ⅱ:创新技术和工程应用[J].水利学报,2016,47(4):483-492.ZONG Dunfeng,LIU Jianfa,XIAO Enshang,et al.60years’perspective of the diaphragm wall technology for seepage control,Part II:Innovation and application[J].Journal of Hydraulic Engineering,2016,47(4):483-492.(in Chinese)
[9]Luo Y,Wu Q,Zhan M,et al.Hydro-mechanical coupling experiments on suffusion in sandy gravel foundations containing a partially penetrating cut-off wall[J].Natural Hazards,2013,67(2):659-674.
[10]Anderson E I.Exact and approximate solutions for seepage through semipermeable cutoff walls[J].International Journal of Geomechanics,2014:04014087.
[11]Xu L,Shen Z,Tang Y.The Seepage characteristics analysis on Xieka Concrete Face Rockfill Dam[J].Physical and Numerical Simulation of Geotechnical Engineering,2012(8):49-51.
[12]Wu Y X,Shen S L,Yin Z Y,et al.Characteristics of groundwater seepage with cut-off wall in gravel aquifer.II:Numerical analysis[J].Canadian Geotechnical Journal,2014,52(10):1539-1549.
[13]Wu Y X,Shen S L,Xu Y S,et al.Characteristics of groundwater seepage with cut-off wall in gravel aquifer.I:Field observations[J].Canadian Geotechnical Journal,2015,52(10):1526-1538.
[14]谢兴华,王国庆.深厚覆盖层坝基防渗墙深度研究[J].岩土力学,2009,30(9):2708-2712.XIE Xinghua,WANG Guoqing.A study of anti-seepage wall depth in thick overburden dam base[J].Rock and Soil Mechanics,2009,30(9):2708-2712.(in Chinese)
[15]郑海圣,周嵩,刘武,等.防渗墙深度对闸坝深厚透水层渗流特性的影响[J].水电能源科学,2013(9):76-78.ZHENG Haisheng,ZHOU Song,LIU Wu,et al.Impact of cutoff wall depth on seepage characteristics of thick permeable layers of gate dam[J].Water Resources and Power,2013(9):76-78.(in Chinese)
[16]Mansuri B,Salmasi F.Effect of horizontal drain length and cutoff wall on seepage and uplift pressure in heterogeneous earth dam with numerical simulation[J].Journal of Civil Engineering&Urbanism,2013,3(3):114-121.
[17]温立峰,范亦农,柴军瑞,等.深厚覆盖层地基渗流控制措施效果数值分析[J].水资源与水工程学报,2014,25(1):127-132.WEN Lifeng,FAN Yinong,CHAI Junrui,et al.Numerical analysis on effect of seepage control measure for deep overburden foundation[J].Journal of Water Resources and Water Engineering,2014,25(1):127-132.(in Chinese)
[18]张文捷,魏迎奇,蔡红.深厚覆盖层垂直防渗措施效果分析[J].水利水电技术,2009,40(7):90-93.ZHANG Wenjie,WEI Yingqi,CAI Hong.Analysis on effect of vertical seepage control measure for deep overburden[J].Water Resources and Hydropower Engineering,2009,40(7):90-93.(in Chinese)
[19]王正成,毛海涛,姜海波,等.弱透水层深度对深厚覆盖层坝基渗控的影响研究[J].人民长江,2016,47(7):54-58.WANG Zhengcheng,MAO Haitao,JIANG Haibo,et al.Effect of weak aquifer depth to seepage prevention of dam foundation on thick overburden layer[J].Yangtze River,2016,47(7):54-58.(in Chinese)
[20]王正成,毛海涛,姜海波,等.深厚覆盖层弱透水层对防渗墙防渗效果的影响[J].人民黄河,2017,39(2):112-115.WANG Zhengcheng,MAO Haitao,JINAG Haibo,et al.Research on the influence of weak aquifer of deep overburden layer to the impermeable effect of cutoff wall[J].Yellow River,2017,39(2):112-115.(in Chinese)
[21]吴梦喜,杨连枝,王锋.强弱透水相间深厚覆盖层坝基的渗流分析[J].水利学报,2013,44(12):1439-1447.WU Mengxi,YANG Lianzhi,WANG Feng.Seepage analysis of dam foundation with deep deposit composed of strong and weak permeable interphase layers alternately[J].Journal of Hydraulic Engineering,2013,44(12):1439-1447.(in Chinese)
[22]李江,李湘权.新疆特殊条件下面板堆石坝和沥青混凝土心墙坝设计施工技术进展[J].水利水电技术,2016,47(3):2-8.LI Jiang,LI Xiangquan.Technical advances in design and construction of concrete face rockfill dam and dam with asphalt concrete core-wall under special condition in Xinjiang[J].Water Resources and Hydropower Engineering,2016,47(3):2-8.(in Chinese)
[23]Wilson G V,Nieber J L,Sidle R C,et al.Internal erosion during soil pipeflow:State of the science for experimental and numerical analysis[J].Transactions of the Asabe,2012,56(2):465-478.
[2]党林才,刘荣丽,王仁坤,等.利用覆盖层建坝的实践与发展[M].北京:中国水利水电出版社,2009.DANG Lincai,LIU Rongli,WANG Renkun,et al.Practice and development of using overburden layers to build dams[M].Beijing:China Water&Power Press,2009.(in Chinese)
[3]高钟璞.大坝基础防渗墙[M].北京:中国电力出版社,2000.GAO Zhongpu.Cutoff wall in dam foundation[M].Beijing:China Electric Power Press,2000.(in Chinese)
[4]沈振中,邱莉婷,周华雷.深厚覆盖层上土石坝防渗技术研究进展[J].水利水电科技进展,2015,35(5):27-35.SHEN Zhenzhong,QIU Liting,ZHOU Hualei.Review of seepage control of earth-rockfill dams on thick overburden layer[J].China Rural Water and Hydropower,2015,35(5):27-35.(in Chinese)
[5]Xi N N,Tong F G,Liu G,et al.Finite element analysis of dam foundation seepage effect on cutoff wall depth of Guxue Concrete Gravity Dam[J].Advanced Materials Research,2014,1073-1076:1729-1732.
[6]白勇,柴军瑞,曹境英,等.深厚覆盖层地基渗流场数值分析[J].岩土力学,2008,29(S1):94-98.BAI Yong,CHAI Junrui,CAO Jingying,et al.Numerical analysis of seepage field in deep overburden foundation[J].Rock and Soil Mechanics,2008,29(S1):94-98.(in Chinese)
[7]宗敦峰,刘建发,肖恩尚,等.水工建筑物防渗墙技术60年Ⅰ:成墙技术和工艺[J].水利学报,2016,47(3):455-462.ZONG Dunfeng,LIU Jianfa,XIAO Enshang,et al.60years’perspective of the diaphragm wall technology for seepage control,Part I:construction method and workmanship[J].Journal of Hydraulic Engineering,2016,47(3):455-462.(in Chinese)
[8]宗敦峰,刘建发,肖恩尚,等.水工建筑物防渗墙技术60年Ⅱ:创新技术和工程应用[J].水利学报,2016,47(4):483-492.ZONG Dunfeng,LIU Jianfa,XIAO Enshang,et al.60years’perspective of the diaphragm wall technology for seepage control,Part II:Innovation and application[J].Journal of Hydraulic Engineering,2016,47(4):483-492.(in Chinese)
[9]Luo Y,Wu Q,Zhan M,et al.Hydro-mechanical coupling experiments on suffusion in sandy gravel foundations containing a partially penetrating cut-off wall[J].Natural Hazards,2013,67(2):659-674.
[10]Anderson E I.Exact and approximate solutions for seepage through semipermeable cutoff walls[J].International Journal of Geomechanics,2014:04014087.
[11]Xu L,Shen Z,Tang Y.The Seepage characteristics analysis on Xieka Concrete Face Rockfill Dam[J].Physical and Numerical Simulation of Geotechnical Engineering,2012(8):49-51.
[12]Wu Y X,Shen S L,Yin Z Y,et al.Characteristics of groundwater seepage with cut-off wall in gravel aquifer.II:Numerical analysis[J].Canadian Geotechnical Journal,2014,52(10):1539-1549.
[13]Wu Y X,Shen S L,Xu Y S,et al.Characteristics of groundwater seepage with cut-off wall in gravel aquifer.I:Field observations[J].Canadian Geotechnical Journal,2015,52(10):1526-1538.
[14]谢兴华,王国庆.深厚覆盖层坝基防渗墙深度研究[J].岩土力学,2009,30(9):2708-2712.XIE Xinghua,WANG Guoqing.A study of anti-seepage wall depth in thick overburden dam base[J].Rock and Soil Mechanics,2009,30(9):2708-2712.(in Chinese)
[15]郑海圣,周嵩,刘武,等.防渗墙深度对闸坝深厚透水层渗流特性的影响[J].水电能源科学,2013(9):76-78.ZHENG Haisheng,ZHOU Song,LIU Wu,et al.Impact of cutoff wall depth on seepage characteristics of thick permeable layers of gate dam[J].Water Resources and Power,2013(9):76-78.(in Chinese)
[16]Mansuri B,Salmasi F.Effect of horizontal drain length and cutoff wall on seepage and uplift pressure in heterogeneous earth dam with numerical simulation[J].Journal of Civil Engineering&Urbanism,2013,3(3):114-121.
[17]温立峰,范亦农,柴军瑞,等.深厚覆盖层地基渗流控制措施效果数值分析[J].水资源与水工程学报,2014,25(1):127-132.WEN Lifeng,FAN Yinong,CHAI Junrui,et al.Numerical analysis on effect of seepage control measure for deep overburden foundation[J].Journal of Water Resources and Water Engineering,2014,25(1):127-132.(in Chinese)
[18]张文捷,魏迎奇,蔡红.深厚覆盖层垂直防渗措施效果分析[J].水利水电技术,2009,40(7):90-93.ZHANG Wenjie,WEI Yingqi,CAI Hong.Analysis on effect of vertical seepage control measure for deep overburden[J].Water Resources and Hydropower Engineering,2009,40(7):90-93.(in Chinese)
[19]王正成,毛海涛,姜海波,等.弱透水层深度对深厚覆盖层坝基渗控的影响研究[J].人民长江,2016,47(7):54-58.WANG Zhengcheng,MAO Haitao,JIANG Haibo,et al.Effect of weak aquifer depth to seepage prevention of dam foundation on thick overburden layer[J].Yangtze River,2016,47(7):54-58.(in Chinese)
[20]王正成,毛海涛,姜海波,等.深厚覆盖层弱透水层对防渗墙防渗效果的影响[J].人民黄河,2017,39(2):112-115.WANG Zhengcheng,MAO Haitao,JINAG Haibo,et al.Research on the influence of weak aquifer of deep overburden layer to the impermeable effect of cutoff wall[J].Yellow River,2017,39(2):112-115.(in Chinese)
[21]吴梦喜,杨连枝,王锋.强弱透水相间深厚覆盖层坝基的渗流分析[J].水利学报,2013,44(12):1439-1447.WU Mengxi,YANG Lianzhi,WANG Feng.Seepage analysis of dam foundation with deep deposit composed of strong and weak permeable interphase layers alternately[J].Journal of Hydraulic Engineering,2013,44(12):1439-1447.(in Chinese)
[22]李江,李湘权.新疆特殊条件下面板堆石坝和沥青混凝土心墙坝设计施工技术进展[J].水利水电技术,2016,47(3):2-8.LI Jiang,LI Xiangquan.Technical advances in design and construction of concrete face rockfill dam and dam with asphalt concrete core-wall under special condition in Xinjiang[J].Water Resources and Hydropower Engineering,2016,47(3):2-8.(in Chinese)
[23]Wilson G V,Nieber J L,Sidle R C,et al.Internal erosion during soil pipeflow:State of the science for experimental and numerical analysis[J].Transactions of the Asabe,2012,56(2):465-478.