深厚强透水含水层超大基坑降水群井效应研究
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摘要
基坑减压降水的幅度与群井效应密切相关。某超大面积基坑,含水层组厚40m,中下部透水性强,采用非完整井降水。对水文地质条件概化,建立了地下水三维非稳定流数值模型,对均匀布置群井、不均匀布置群井、分块开挖降水、不同的井结构、布设回灌井等工况,进行了渗流场模拟。研究表明,强透水性含水层超大面积基坑降水的群井效应极为明显;井位角密中疏布置,可实现降深调平,避免降深不足和超降;基坑分块降水,可减少坑外降深;短滤管井结构可减少基坑总涌水量和坑外降深;强透水性含水层可灌性强,回灌对减少坑外水位下降有较明显的效果。模拟结果与现场监测较为一致。研究成果可为类似工程地下水控制设计提供参考。
Water head drawdown during dewatering in confined aquifers closely relates to multi-well effect. An ultra-large pit is studied in this paper. The pit features 40-meter-thick aquifers,is high permeability at middle and down side,and uses partial pumping wells. Based on the summarization of hydrogeological conditions,a three dimensional unsteady-flow numerical model of underground water is built and used to simulate the seepage field under different scenarios. They include even and uneven distribution of wells,excavation and dewatering by blocks,various well structures and deployment of injection wells. The research shows( 1) Ultra-large pit in highly permeable aquifers has obvious multi-well effect;( 2) "Dense at Corner and Sparse at Center"well deployment unifies water head drawdown and avoids insufficient or excessive dewatering;( 3) Excavation and dewatering by blocks suppresses drawdown outside the pit;( 4) Well structure with short screen pipe reduces total water yield and suppresses outside drawdown;( 5) Aquifers of high permeability are highly rechargeable and recharging has fairly obvious effect on suppressing outside drawdown. Simulation results are consistent with in-situ monitoring. The research result can serve as a reference to similar underground water level control project.
Water head drawdown during dewatering in confined aquifers closely relates to multi-well effect. An ultra-large pit is studied in this paper. The pit features 40-meter-thick aquifers,is high permeability at middle and down side,and uses partial pumping wells. Based on the summarization of hydrogeological conditions,a three dimensional unsteady-flow numerical model of underground water is built and used to simulate the seepage field under different scenarios. They include even and uneven distribution of wells,excavation and dewatering by blocks,various well structures and deployment of injection wells. The research shows( 1) Ultra-large pit in highly permeable aquifers has obvious multi-well effect;( 2) "Dense at Corner and Sparse at Center"well deployment unifies water head drawdown and avoids insufficient or excessive dewatering;( 3) Excavation and dewatering by blocks suppresses drawdown outside the pit;( 4) Well structure with short screen pipe reduces total water yield and suppresses outside drawdown;( 5) Aquifers of high permeability are highly rechargeable and recharging has fairly obvious effect on suppressing outside drawdown. Simulation results are consistent with in-situ monitoring. The research result can serve as a reference to similar underground water level control project.
引文
Chen W H,Xu A G,Ma L L,et al.1993.Application of optimizationmethod in groundwater drawdown project for deep excavation[J].Chinese Journal of Geotechnical Engineering,15(3):37~45.
Ding P Z,Xiao L,Li W,et al.2012.Design of dewatering plans fordeep excavation pit in thick permeable strata[J].Journal of YangtzeRiver Scientific Research Institute,29(2):46~50.
Fan S K,Yang Y W.2010.Ground water control and practice of deepfoundation pits in 1stterrace along Yangtze river[J].Chinese Journalof Geotechnical Engineering,32(S):63~69.
Lu Z Q,Feng X L,Wang C F.2006.Effects of pensile curtain ondewatering of foundation pits[J].Tunnel Construction,26(5):5~7.
Luo Z J,Li L,Cao H B,et al.2006.Numerical simulation of threedimensional seepage field of a deep foundation pit during dewateringin a complex composite aquifer system:Case study of a pit at theShanghai Finace Center[J].Journal of Engineering Geology,14(1):72~77.
Luo Z J,Zhang Y P,Liu J B.2007.Three dimensional seepagenumerical simulation of deep foundation pit dewatering incomplicated quaternary loose sediments with great thickness:A casestudy of dewatering reconstructed foundation pit at Dongjiadu subwayof the 4thline in Shanghai[J].Chinese Journal of Rock Mechanicsand Engineering,26(S1):2907~2914.
Miao J F,Lou R X,Fang Z C.2010.Design methods of dewatering ofconfined aquifers in Shanghai area[J].Chinese JournalUnderground Space and Engineering,6(1):167~173.
Pan W Q.2013.Composite construction technology of pumping andirrigation of confined water for supet-deep foundation excavatiou softsoil area[J].Construction Tecnology,2013,42(S):99~103.
Qu C S,Chen W,Huang Y.2011.Numerical simulation for subsidenceof deep foundation pits controlled by artificial groundwaterrecharge[J].Periodical of Ocean University of China,41(6):87~92.
Wang C Y,Feng X L,Wang J W.2004.Hydrologic and geologiccharacteristics of medium and weak permeable layer in binarystructural area in Hankou administrative region of Wuhan city[J].Yangtze River,35(9):27~29.
Wang X K,Zhao Y Z,Liu H F,et al.2013.The new injection techniqueof the water heat pump system in the medium-fine sand aquifer in theZhengbian new region[J].Hydrogeology and Engineering Geology,40(3):136~140.
Wu J Z,Wang H M,Yang T L.2009.Experimental research on artificialrecharge to shallow aquifer to control land subsidence due toconstruction in Shanghai city[J].Geoscience,23(6):1190~1200.
Yang G X.2009.Dewatering of deep foundation pit of underground mallof Wuhan International Expo.Center[A]∥Liu G B,Wang W D.Handbook of excavation(Second Edition)[M].Beijing:ChinaArchitecture and Building Press,849~850.
Yuan H,Zhang Q H.2013.Optimization design and application ofdewatering—Recharge system in deep excavation[J].Journal ofShanghai Jiaotong University,47(9):1424~1429.
Yuan X,Gong Q M,Shi J S,et al.2011.Analysis on pressure-relief ofhigh artesian water pressure in gravel soil deep pit[J].Journal ofCivil Architectural and Environmental Engineering.33(S1):185~190.
Zhang X C,Zhang J,Gong X N,et al.2010.Regional property ofconfined aquifer in typical cities[J].Journal of Zhejiang University(Engineering Science),44(10):1998~2004.
Zhou N Q,Tang Y Q,Lou R X,et al.2011.Numerical simulation ofdeep foundation pit dewatering and land subsidence control ofXujiahui metro station[J].Chinese Journal of GeotechnicalEngineering,33(12):1950~1956.
Zhu X D,Zhou Z.2010.Design of dewatering proposal for confined waterin super lager-scale deep foundation pit[J].Building Construction,32(4):257~279.
陈文华,许爱国,马丽丽,等,1993.最优化法在深基坑降水工程中的应用[J].岩土工程学报,15(3):37~45.
定培中,肖利,李威,等.2012.深厚透水性地层中大型深基坑降水方案设计探讨[J].长江科学院院报,29(2):46~50.
范士凯,杨育文.2010.长江一级阶地基坑地下水控制方法和实践[J].岩土工程学报,32(增):63~69.
瞿成松,陈蔚,黄雨.2011.人工回灌控制基坑工程地面沉降的数值模拟[J].中国海洋大学学报,41(6):87~92.
卢智强,冯晓腊,王超峰.2006.悬挂式止水帷幕对基坑降水的影响[J].隧道建设,26(5):5~7.
骆祖江,李朗,曹惠宾,等.2006.复合含水层地区深基坑降水三维渗流场数值模拟———以上海环球金融中心基坑降水为例[J].工程地质学报,14(1):72~77.
骆祖江,张月萍,刘金宝.2007.复杂巨大厚第四纪松散沉积层地区深基坑降水三维渗流场数值模拟———以上海地铁4#线董家渡段隧道修复基坑降水为例[J].岩石力学与工程学报,26(增):2907~2914.
缪俊发,娄荣祥,方兆昌.2010.上海地区承压含水层降水设计方法[J].地下空间与工程学报,6(1):167~173.
潘伟强.2013.软土地区超深基坑压水抽-灌一体化施工技术[J].施工技术,42(增):99~103.
王翠英,冯晓腊,王继伟.2004.二元结构中弱透水层基坑降水的水文地质特性[J].人民长江,35(9):27~29.
王献坤,赵云章,刘海风,等,2013.郑汴新区中细砂含水层水源热泵井回灌新技术[J].水文地质工程地质,40(3):136~140.
吴建中,王寒梅,杨天亮.2009.浅层地下水人工回灌应用于上海市工程性地面沉降防治的试验研究[J].现代地质,23(6):1194~1200.
杨光煦.2009.武汉国际会展中心地下商场深基坑工程降水[A]∥刘国彬,王卫东.基坑工程手册(第二版)[M].北京:中国建筑工业出版社,849~850.
元翔,宫全美,石景山,等.2011.卵砾石地层深基坑高承压水降压方案分析[J].土木建筑与环境工程,33(增1):185~190.
原华,张庆贺.2013.深基坑降水-回灌系统的最优化设计与应用[J].上海交通大学学报,47(9):1424~1429.
张雪婵,张杰,龚晓南,等.2010.典型城市承压含水层区域性特性[J].浙江大学学报(工学报),44(10):1998~2004.
周念清,唐益群,娄荣祥,等.2011.徐家汇地铁站深基坑降水数值模拟与沉降控制[J].岩土工程学报,33(12):1950~1956.
朱旭东,周振.2010.超大型深基坑承压水降水方案设计[J].建筑施工,32(4):275~279.
Ding P Z,Xiao L,Li W,et al.2012.Design of dewatering plans fordeep excavation pit in thick permeable strata[J].Journal of YangtzeRiver Scientific Research Institute,29(2):46~50.
Fan S K,Yang Y W.2010.Ground water control and practice of deepfoundation pits in 1stterrace along Yangtze river[J].Chinese Journalof Geotechnical Engineering,32(S):63~69.
Lu Z Q,Feng X L,Wang C F.2006.Effects of pensile curtain ondewatering of foundation pits[J].Tunnel Construction,26(5):5~7.
Luo Z J,Li L,Cao H B,et al.2006.Numerical simulation of threedimensional seepage field of a deep foundation pit during dewateringin a complex composite aquifer system:Case study of a pit at theShanghai Finace Center[J].Journal of Engineering Geology,14(1):72~77.
Luo Z J,Zhang Y P,Liu J B.2007.Three dimensional seepagenumerical simulation of deep foundation pit dewatering incomplicated quaternary loose sediments with great thickness:A casestudy of dewatering reconstructed foundation pit at Dongjiadu subwayof the 4thline in Shanghai[J].Chinese Journal of Rock Mechanicsand Engineering,26(S1):2907~2914.
Miao J F,Lou R X,Fang Z C.2010.Design methods of dewatering ofconfined aquifers in Shanghai area[J].Chinese JournalUnderground Space and Engineering,6(1):167~173.
Pan W Q.2013.Composite construction technology of pumping andirrigation of confined water for supet-deep foundation excavatiou softsoil area[J].Construction Tecnology,2013,42(S):99~103.
Qu C S,Chen W,Huang Y.2011.Numerical simulation for subsidenceof deep foundation pits controlled by artificial groundwaterrecharge[J].Periodical of Ocean University of China,41(6):87~92.
Wang C Y,Feng X L,Wang J W.2004.Hydrologic and geologiccharacteristics of medium and weak permeable layer in binarystructural area in Hankou administrative region of Wuhan city[J].Yangtze River,35(9):27~29.
Wang X K,Zhao Y Z,Liu H F,et al.2013.The new injection techniqueof the water heat pump system in the medium-fine sand aquifer in theZhengbian new region[J].Hydrogeology and Engineering Geology,40(3):136~140.
Wu J Z,Wang H M,Yang T L.2009.Experimental research on artificialrecharge to shallow aquifer to control land subsidence due toconstruction in Shanghai city[J].Geoscience,23(6):1190~1200.
Yang G X.2009.Dewatering of deep foundation pit of underground mallof Wuhan International Expo.Center[A]∥Liu G B,Wang W D.Handbook of excavation(Second Edition)[M].Beijing:ChinaArchitecture and Building Press,849~850.
Yuan H,Zhang Q H.2013.Optimization design and application ofdewatering—Recharge system in deep excavation[J].Journal ofShanghai Jiaotong University,47(9):1424~1429.
Yuan X,Gong Q M,Shi J S,et al.2011.Analysis on pressure-relief ofhigh artesian water pressure in gravel soil deep pit[J].Journal ofCivil Architectural and Environmental Engineering.33(S1):185~190.
Zhang X C,Zhang J,Gong X N,et al.2010.Regional property ofconfined aquifer in typical cities[J].Journal of Zhejiang University(Engineering Science),44(10):1998~2004.
Zhou N Q,Tang Y Q,Lou R X,et al.2011.Numerical simulation ofdeep foundation pit dewatering and land subsidence control ofXujiahui metro station[J].Chinese Journal of GeotechnicalEngineering,33(12):1950~1956.
Zhu X D,Zhou Z.2010.Design of dewatering proposal for confined waterin super lager-scale deep foundation pit[J].Building Construction,32(4):257~279.
陈文华,许爱国,马丽丽,等,1993.最优化法在深基坑降水工程中的应用[J].岩土工程学报,15(3):37~45.
定培中,肖利,李威,等.2012.深厚透水性地层中大型深基坑降水方案设计探讨[J].长江科学院院报,29(2):46~50.
范士凯,杨育文.2010.长江一级阶地基坑地下水控制方法和实践[J].岩土工程学报,32(增):63~69.
瞿成松,陈蔚,黄雨.2011.人工回灌控制基坑工程地面沉降的数值模拟[J].中国海洋大学学报,41(6):87~92.
卢智强,冯晓腊,王超峰.2006.悬挂式止水帷幕对基坑降水的影响[J].隧道建设,26(5):5~7.
骆祖江,李朗,曹惠宾,等.2006.复合含水层地区深基坑降水三维渗流场数值模拟———以上海环球金融中心基坑降水为例[J].工程地质学报,14(1):72~77.
骆祖江,张月萍,刘金宝.2007.复杂巨大厚第四纪松散沉积层地区深基坑降水三维渗流场数值模拟———以上海地铁4#线董家渡段隧道修复基坑降水为例[J].岩石力学与工程学报,26(增):2907~2914.
缪俊发,娄荣祥,方兆昌.2010.上海地区承压含水层降水设计方法[J].地下空间与工程学报,6(1):167~173.
潘伟强.2013.软土地区超深基坑压水抽-灌一体化施工技术[J].施工技术,42(增):99~103.
王翠英,冯晓腊,王继伟.2004.二元结构中弱透水层基坑降水的水文地质特性[J].人民长江,35(9):27~29.
王献坤,赵云章,刘海风,等,2013.郑汴新区中细砂含水层水源热泵井回灌新技术[J].水文地质工程地质,40(3):136~140.
吴建中,王寒梅,杨天亮.2009.浅层地下水人工回灌应用于上海市工程性地面沉降防治的试验研究[J].现代地质,23(6):1194~1200.
杨光煦.2009.武汉国际会展中心地下商场深基坑工程降水[A]∥刘国彬,王卫东.基坑工程手册(第二版)[M].北京:中国建筑工业出版社,849~850.
元翔,宫全美,石景山,等.2011.卵砾石地层深基坑高承压水降压方案分析[J].土木建筑与环境工程,33(增1):185~190.
原华,张庆贺.2013.深基坑降水-回灌系统的最优化设计与应用[J].上海交通大学学报,47(9):1424~1429.
张雪婵,张杰,龚晓南,等.2010.典型城市承压含水层区域性特性[J].浙江大学学报(工学报),44(10):1998~2004.
周念清,唐益群,娄荣祥,等.2011.徐家汇地铁站深基坑降水数值模拟与沉降控制[J].岩土工程学报,33(12):1950~1956.
朱旭东,周振.2010.超大型深基坑承压水降水方案设计[J].建筑施工,32(4):275~279.