地震作用下渗流对平原水库土石坝稳定的影响
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摘要
平原水库的土石坝在坝基中普遍存在着可液化的土层,地震作用下坝基液化问题及其对大坝稳定的影响是一个人们普遍关注的问题。为此,以天津尔王庄水库这一典型平原水库为工程背景,在室内和现场试验的基础上,对土层液化可能性进行判别,对土层的动力特性进行研究,同时对渗流场在地震作用下的变化进行初步探讨。试验结果显示,在研究区域内的可液化土层在7度地震烈度下有发生液化的可能性。此外,模型试验显示渗流场在地震作用下会发生变化,但在本次计算条件下,渗流场的变化不大。根据室内试验得到的各种参数,利用数值计算方法对渗流在地震作用下所起的作用进行分析。分析结果显示,计算所得到的液化区域深度与试验结果相符。土层的分布对液化区域大小与位置的影响明显,考虑和不考虑渗流对液化区域的影响不大;但是,考虑渗流会使迎水坡的安全系数提高,背水坡的安全系数下降。同时,在一定区域内,在考虑渗流的情况下,土体的水平位移也有增大的趋势。
The soil layers with liquefaction characteristics can be often found in the foundation of earth-rock dam in plain area. The soil liquefaction under seismic loading and its influence on the stability of the dam are important issues. The Erwangzhuang reservoir dam,a typical earth-rock dam in plain area,is chosen as an example to study the problem. Based on the indoor and in-situ tests,the liquefaction possibility of the soil layers,the dynamic properties of soil and the change of seepage field in the soil under earthquake are all concerned. The in-situ test results show that under seismic loading with magnitude 7,some in-situ soil layers could be liquefied. The results of indoor model tests show that the seepage field in the soil is changed under vibration;but the change of seepage field is not obvious. Utilizing the soil parameters obtained by indoor tests,the dynamic numerical analysis is performed with/without considering seepage. The numerical results show that the depth of liquefied zone agrees with the results of tests. The size of liquefaction region in the foundation is affected by the distribution of soil layers remarkably;yet the seepage influence is not obvious. When considering seepage,the factor of safety of upstream increases and the factor of safety of downstream will decrease. The influence of the seepage on the horizontal displacement can also be found at the same time.
The soil layers with liquefaction characteristics can be often found in the foundation of earth-rock dam in plain area. The soil liquefaction under seismic loading and its influence on the stability of the dam are important issues. The Erwangzhuang reservoir dam,a typical earth-rock dam in plain area,is chosen as an example to study the problem. Based on the indoor and in-situ tests,the liquefaction possibility of the soil layers,the dynamic properties of soil and the change of seepage field in the soil under earthquake are all concerned. The in-situ test results show that under seismic loading with magnitude 7,some in-situ soil layers could be liquefied. The results of indoor model tests show that the seepage field in the soil is changed under vibration;but the change of seepage field is not obvious. Utilizing the soil parameters obtained by indoor tests,the dynamic numerical analysis is performed with/without considering seepage. The numerical results show that the depth of liquefied zone agrees with the results of tests. The size of liquefaction region in the foundation is affected by the distribution of soil layers remarkably;yet the seepage influence is not obvious. When considering seepage,the factor of safety of upstream increases and the factor of safety of downstream will decrease. The influence of the seepage on the horizontal displacement can also be found at the same time.
引文
[1]邱战洪,张我华,任廷鸿.地震在和作用下大坝系统的非线性动力损伤分析[J].水利学报,2005,36(5):629–636.(QIU Zhanhong,ZHANG Wohua,REN Tinghong.Nonlinear dynamic damage analysis of dam and rock foundation under the action of earthquake[J].Journal of Hydraulic Engineering,2005,36(5):629–636.(in Chinese))
[2]段小波.混凝土重力坝抗震优化设计[硕士学位论文][D].南京:河海大学,2004.(DUAN Xiaobo.The optimal design of concrete gravity dam under earthquake[M.S.Thesis][D].Nanjing:Hohai University,2004.(in Chinese))
[3]LOTFI V,ROESSET J M,TASSOULAS J L.A technique for the analysis of the response of dams to earthquake[J].Earthquake Engineering and Structure Dynamics,1987,15(4):463–490.
[4]CHEN B F,YUAN Y S,LEE J F.Three-dimensional nonlinear hydrodynamic pressures by earthquake on dam face with arbitrary reservoir shapes[J].Journal of Hydraulic Research,1999,37(2):163–187.
[5]VALLIAPPAN S.Computational mechanics applied to interaction problem[J].International Journal for Numerical Methods in Engineering,2004,60(2):361–379.
[6]WANG X,WANG L B.Dynamic analysis of a water-soil-pore water coupling system[J].Computers and Structures,2007,85(14):1020–1031.
[7]杜荣强,林皋,胡志强.混凝土重力坝弹塑性损伤安全评价[J].水利学报,2006,37(9):1056–1062.(DU Rongqiang,LIN Gao,HU Zhiqiang.Safety assessment of concrete gravity dams based on dynamic elastoplatic damage analysis[J].Journal of Hydraulic Engineering,2006,37(9):1056–1062.(in Chinese))
[8]林皋.混凝土大坝抗震安全评价的发展趋向[J].防灾减灾工程学报,2006,26(1):1–12.(LIN Gao.Developing tendency of the seismic safety evaluation of large concrete dams[J].Journal of Disaster Prevention and Mitigation Engineering,2006,26(1):1–12.(in Chinese))
[9]WANG Z L,MAKDISI F,EQAN J.Practical applications of a nonlinear approach to analysis of earthquake-induced liquefaction and deformation of earth structures[J].Soil Dynamics and Earthquake Engineering,2006,26(2/4):231–252.
[10]SHARP M K,ADALIER K.Seismic response of earth dam with varying depth of liquefiable foundation layer[J].Soil Dynamics and Earthquake Engineering,2006,26(11):1028–1037.
[11]LI X S,MING H Y.Seepage driving effect on deformations of San Fernando dams[J].Soil Dynamics and Earthquake Engineering,2004,24(5):979–992.
[12]天津大学.尔王庄水库地质勘查报告[R].天津:天津大学,2001.(Tianjin University.The soil investigation report of Erwangzhuang reservoir[R].Tianjin:Tianjin University,2001.(in Chinese))
[13]中华人民共和国行业标准编写组.DBTJ29–20–2000岩土工程技术规范[S].北京:中国建筑工业出版社,2000.(The Professional Standards Compilation Group of People′s Republic of China.DBTJ29–20–2000Technical code of geotechnical engineering[S].Beijing:China Architecture and Building Press,2000.(in Chinese))
[14]中华人民共和国国家标准编写组.GB50287–99水利水电工程地质勘察规范[S].北京:中国计划出版社,1999.(The National Standards Compilation Group of People′s Republic of China.GB50287–99Code for water resources and hydropower engineering geological investigation[S].Beijing:China Planning Press,1999.(in Chinese))
[15]中华人民共和国国家标准编写组.GB50011–2001建筑抗震设计规范[S].北京:中国建筑工业出版社,2001.(The National Standards Compilation Group of People′s Republic of China.GB50011–2001Code for seismic design of buildings[S].Beijing:China Architecture and Building Press,2001.(in Chinese))
[16]郭抗美.随机地震作用下天津饱和粉土动力特性及其液化预测方法[硕士学位论文][D].天津:天津大学,1998.(GUO Kangmei.Dynamic properties and forecast methods for saturated liquefied silt in Tianjin under earthquake[M.S.Thesis][D].Tianjin:Tianjin University,1998.(in Chinese))
[2]段小波.混凝土重力坝抗震优化设计[硕士学位论文][D].南京:河海大学,2004.(DUAN Xiaobo.The optimal design of concrete gravity dam under earthquake[M.S.Thesis][D].Nanjing:Hohai University,2004.(in Chinese))
[3]LOTFI V,ROESSET J M,TASSOULAS J L.A technique for the analysis of the response of dams to earthquake[J].Earthquake Engineering and Structure Dynamics,1987,15(4):463–490.
[4]CHEN B F,YUAN Y S,LEE J F.Three-dimensional nonlinear hydrodynamic pressures by earthquake on dam face with arbitrary reservoir shapes[J].Journal of Hydraulic Research,1999,37(2):163–187.
[5]VALLIAPPAN S.Computational mechanics applied to interaction problem[J].International Journal for Numerical Methods in Engineering,2004,60(2):361–379.
[6]WANG X,WANG L B.Dynamic analysis of a water-soil-pore water coupling system[J].Computers and Structures,2007,85(14):1020–1031.
[7]杜荣强,林皋,胡志强.混凝土重力坝弹塑性损伤安全评价[J].水利学报,2006,37(9):1056–1062.(DU Rongqiang,LIN Gao,HU Zhiqiang.Safety assessment of concrete gravity dams based on dynamic elastoplatic damage analysis[J].Journal of Hydraulic Engineering,2006,37(9):1056–1062.(in Chinese))
[8]林皋.混凝土大坝抗震安全评价的发展趋向[J].防灾减灾工程学报,2006,26(1):1–12.(LIN Gao.Developing tendency of the seismic safety evaluation of large concrete dams[J].Journal of Disaster Prevention and Mitigation Engineering,2006,26(1):1–12.(in Chinese))
[9]WANG Z L,MAKDISI F,EQAN J.Practical applications of a nonlinear approach to analysis of earthquake-induced liquefaction and deformation of earth structures[J].Soil Dynamics and Earthquake Engineering,2006,26(2/4):231–252.
[10]SHARP M K,ADALIER K.Seismic response of earth dam with varying depth of liquefiable foundation layer[J].Soil Dynamics and Earthquake Engineering,2006,26(11):1028–1037.
[11]LI X S,MING H Y.Seepage driving effect on deformations of San Fernando dams[J].Soil Dynamics and Earthquake Engineering,2004,24(5):979–992.
[12]天津大学.尔王庄水库地质勘查报告[R].天津:天津大学,2001.(Tianjin University.The soil investigation report of Erwangzhuang reservoir[R].Tianjin:Tianjin University,2001.(in Chinese))
[13]中华人民共和国行业标准编写组.DBTJ29–20–2000岩土工程技术规范[S].北京:中国建筑工业出版社,2000.(The Professional Standards Compilation Group of People′s Republic of China.DBTJ29–20–2000Technical code of geotechnical engineering[S].Beijing:China Architecture and Building Press,2000.(in Chinese))
[14]中华人民共和国国家标准编写组.GB50287–99水利水电工程地质勘察规范[S].北京:中国计划出版社,1999.(The National Standards Compilation Group of People′s Republic of China.GB50287–99Code for water resources and hydropower engineering geological investigation[S].Beijing:China Planning Press,1999.(in Chinese))
[15]中华人民共和国国家标准编写组.GB50011–2001建筑抗震设计规范[S].北京:中国建筑工业出版社,2001.(The National Standards Compilation Group of People′s Republic of China.GB50011–2001Code for seismic design of buildings[S].Beijing:China Architecture and Building Press,2001.(in Chinese))
[16]郭抗美.随机地震作用下天津饱和粉土动力特性及其液化预测方法[硕士学位论文][D].天津:天津大学,1998.(GUO Kangmei.Dynamic properties and forecast methods for saturated liquefied silt in Tianjin under earthquake[M.S.Thesis][D].Tianjin:Tianjin University,1998.(in Chinese))
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