泸定大渡河桥康定岸重力锚边坡长期变形与稳定性分析
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摘要
悬索桥重力式锚碇边坡的长期变形与稳定性是影响该类桥梁结构正常使用的一个关键要素。为合理讨论这一问题,以泸定大渡河桥康定岸重力式锚碇边坡为例,首先开展了现场边坡土体剪切、压缩试验,通过三维弹塑性数值模拟方法确定坡体应力场,基于此确定直剪蠕变试验加载条件,进而针对主要由冰碛土构成的该坡体,进行直剪蠕变试验,根据试验结果揭示的土体蠕变特性随时间逐渐减弱的特征,结合Mohr-Coulomb强度准则,采用Burgers体与广义Kelvin体组成的两时段蠕变本构模型进行锚碇边坡的黏弹塑性分析。考虑锚碇发挥正常使用功能的要求,提出了特征点(散索鞍点)位移容许值判据,将强度折减法扩展应用于黏弹塑性坡体的长期变形与稳定性分析。实例分析表明,该锚碇在正常运营100 a时散索鞍点朝河侧水平位移为13. 91 cm,在正常使用极限状态的条件下,锚碇边坡的长期稳定系数为1. 71。
The long-term deformation and stability of gravity anchorage slope is one of the most important problems affecting the natural serviceability of the suspension bridge engineering. In order to discuss the problem reasonably,the gravity anchorage slope on Kangding Bank of Dadu River Bridge in Luding is taken as an engineering example.Firstly,in-situ shear and compression tests of the slope soil are carried out. The stress field of the gravity anchorage slope is obtained with three-dimensional elastoplastic numerical simulation method. Based on these results,the loading conditions of the direct shear creep test are determined. Then the direct shear creep test is carried out for the slope mainly composed of moraine soil. The creep test results show creep behaviour of the moraine soil decreases with time. In light of the creep characteristics of the soil,time-dependent combination constitutive models consist of Burgers and general Kelvin model individually with Mohr-Coulomb strength principle is proposed and applied in visco-elastic-plastic numerical simulation analysis of the slope. Considering the requirements of natural serviceability of the anchorage,the criterion of allowable displacement at its unique point( saddle point of the anchorage) is applied. The shear strength reduction method for long-term deformation and stability analysis of the slope is also used. The results of the practical example obtained using the present method show horizontal displacement towards the river of the saddle point is 13. 19 cm when the anchorage-slope system has naturally served for 100 years. The long-term stability coefficient of the system is 1. 71 to meet the requirement of its natural serviceability limit state.
The long-term deformation and stability of gravity anchorage slope is one of the most important problems affecting the natural serviceability of the suspension bridge engineering. In order to discuss the problem reasonably,the gravity anchorage slope on Kangding Bank of Dadu River Bridge in Luding is taken as an engineering example.Firstly,in-situ shear and compression tests of the slope soil are carried out. The stress field of the gravity anchorage slope is obtained with three-dimensional elastoplastic numerical simulation method. Based on these results,the loading conditions of the direct shear creep test are determined. Then the direct shear creep test is carried out for the slope mainly composed of moraine soil. The creep test results show creep behaviour of the moraine soil decreases with time. In light of the creep characteristics of the soil,time-dependent combination constitutive models consist of Burgers and general Kelvin model individually with Mohr-Coulomb strength principle is proposed and applied in visco-elastic-plastic numerical simulation analysis of the slope. Considering the requirements of natural serviceability of the anchorage,the criterion of allowable displacement at its unique point( saddle point of the anchorage) is applied. The shear strength reduction method for long-term deformation and stability analysis of the slope is also used. The results of the practical example obtained using the present method show horizontal displacement towards the river of the saddle point is 13. 19 cm when the anchorage-slope system has naturally served for 100 years. The long-term stability coefficient of the system is 1. 71 to meet the requirement of its natural serviceability limit state.
引文
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Gasc-Barbier M,Chanchole S,Bérest P.2004.Creep behavior of Bure clayey rock[J].Applied Clay Science,26(1):449-458.
Griffiths D V,Lane P A.2001.Slope stability analysis by finite elements[J].Géotechnique,51(7):653-654.
Haupt M.1991.A constitutive law for rock salt based on creep and relaxation tests[J].Rock Mechanics and Rock Engineering,24(4):179-206.
Ito H,Sasajima S.1987.A ten year creep experiment on small rock specimens[J].International Journal of Rock Mechanics and Mining Science&Geomechanics Abstracts,24(2):113-121.
Kang W X,Yu H C,Wang L L,et al.2016.Experimental study of influence of water on creep properties of silty mudstone under triaxial compression[J].Journal of Engineering Geology,24(4):622-628.
Li W S,Zhou H M,Zhong Z W,et al.2012.Development of rock mass true-triaxial site creep testing system and its application[J].Chinese Journal of Rock Mechanics and Engineering,31(8):1636-1641.
Lian Z Y,Han G C,Kong X J.2001.Stability analysis of excavation by strength reduction FEM[J].Chinese Journal of Geotechnical Engineering,23(4):407-411.
Manzari M T,Nour M A.2000.Significance of soil dilatancy in slope stability analysis[J].Journal of Geotechnical and Geoenvironmental Engineering,126(1):75-80.
Maranini E,Brignoli M.1999.Creep behaviour of a weak rock.Experimental characterization[J].International Journal of Rock Mechanics and Mining Sciences,36(1):127-138.
Ruan H F,Luo Q,Meng W C,et al.2016.Analysis of time-effect characteristics of soil deformation and its classification based on direct shear test[J].Rock and Soil Mechanics,37(2):453-464.
Tan T K.1982.The mechanical problems for the long-term stability of underground galleries[J].Chinese Journal of Rock Mechanics and Engineering,1(1):1-20.
The National Standards Compilation Group of People's Repulic of China.2012.Code for design of building foundation[S].Beijing:China Architecture and Building Press.
Wang R B,Xu W Y,Meng Y D,et al.2014.Numerical analysis of longterm stability of left bank abutment high slope at JinpingⅠhydropower station[J].Chinese Journal of Rock Mechanics and Engineering,33(S1):3105-3113.
Yan C G,Li W,Zhao Z X,et al.2017.Impact analysis of creep movement of Zhengjiawan landslide to bridge across[J].Journal of Engineering Geology,25(2):416-423.
Yan G M.1986.A summary of the liaison bridges of Honshu and Shikoku[J].World Bridges,(2):1-17.
Yang J C.2016.Stability analysis of slope for gravity anchorage suspension bridge across Dadu River in Luding county[D].Chengdu:Southwest Jiaotong University.
Zhang G P,Zhou Z,Jiang Q H,et al.2017.Study on time-dependent deformation behavior and long-term stability of a 500 m-level super high slope[J].Chinese Journal of Underground Space and Engineering,13(6):1688-1694.
Zhang Q Y,Chen F,Yang W D,et al.2011.Field shear creep test and creep parameters inversion for dam zone rock mass of Dagangshan Hydropower Station[J].Rock and Soil Mechanics,32(9):2584-2590,2602.
Zhang Q Z,Shen M R,Ding W Q.2012.Study of mechanical properties and long-term strength of Jinping green schist[J].Chinese Journal of Rock Mechanics and Engineering,31(8):1642-1649.
Zhao H,Li W L,Wei J J,et al.2018.Model test study on toppling deformation evolution process of counter-tilt slope[J].Journal of Engineering Geology,26(3):749-757.
Zheng Y R,Zhao S Y.2004.Application of strength reduction FEM in soil and rock slope[J].Chinese Journal of Rock Mechanics and Engineering,23(19):3381-3388.
Zienkiewicz O C,Humpheson C,Lewis R W.1975.Associated and nonassociated visco plasticity and plasticity in soil mechanics[J].Géotechnique,25(4):671-689.
陈卫兵,郑颖人,冯夏庭,等.2008.考虑岩土体流变特性的强度折减法研究[J].岩土力学,29(1):101-105.
陈宗基.1982.地下巷道长期稳定性的力学问题[J].岩石力学与工程学报,1(1):7-26.
康文献,于怀昌,王玲玲,等.2016.三轴应力下水对粉砂质泥岩蠕变力学特性影响作用试验研究[J].工程地质学报,24(4):622-628.
李维树,周火明,钟作武,等.2012.岩体真三轴现场蠕变试验系统研制与应用[J].岩石力学与工程学报,31(8):1636-1641.
连镇营,韩国城,孔宪京.2001.强度折减有限元法研究开挖边坡的稳定性[J].岩土工程学报,23(4):407-411.
阮红风,罗强,孟伟超,等.2016.基于直剪试验的土体变形时间效应及状态类别分析[J].岩土力学,37(2):453-464.
王如宾,徐卫亚,孟永东,等.2014.锦屏一级水电站左岸坝肩高边坡长期稳定性数值分析[J].岩石力学与工程学报,33(S1):3105-3113.
严国敏.1986.日本本州四国联络桥综述[J].国外桥梁,(2):1-17.
晏长根,李为,赵珍祥,等.2017.郑家湾滑坡体蠕变对上跨桥梁的影响分析[J].工程地质学报,25(2):416-423.
杨锦程.2016.泸定大渡河悬索桥重力式锚碇边坡稳定性分析[D].成都:西南交通大学.
张公平,周钟,姜清辉,等.2017.500 m级超高边坡时效变形特征及长期稳定性研究[J].地下空间与工程学报,13(6):1688-1694.
张强勇,陈芳,杨文东,等.2011.大岗山坝区岩体现场剪切蠕变试验及参数反演[J].岩土力学,32(9):2584-2590,2602.
张清照,沈明荣,丁文其.2012.锦屏绿片岩力学特性及长期强度特性研究[J].岩石力学与工程学报,31(8):1642-1649.
赵华,李文龙,卫俊杰,等.2018.反倾边坡倾倒变形演化过程的模型试验研究[J].工程地质学报,26(3):749-757.
郑颖人,赵尚毅.2004.有限元强度折减法在土坡与岩坡中的应用[J].岩石力学与工程学报,23(19):3381-3388.
中华人民共和国行业标准编写组.2012.建筑地基基础设计规范(GB50007-2011)[S].北京:中国建筑工业出版社.
Gasc-Barbier M,Chanchole S,Bérest P.2004.Creep behavior of Bure clayey rock[J].Applied Clay Science,26(1):449-458.
Griffiths D V,Lane P A.2001.Slope stability analysis by finite elements[J].Géotechnique,51(7):653-654.
Haupt M.1991.A constitutive law for rock salt based on creep and relaxation tests[J].Rock Mechanics and Rock Engineering,24(4):179-206.
Ito H,Sasajima S.1987.A ten year creep experiment on small rock specimens[J].International Journal of Rock Mechanics and Mining Science&Geomechanics Abstracts,24(2):113-121.
Kang W X,Yu H C,Wang L L,et al.2016.Experimental study of influence of water on creep properties of silty mudstone under triaxial compression[J].Journal of Engineering Geology,24(4):622-628.
Li W S,Zhou H M,Zhong Z W,et al.2012.Development of rock mass true-triaxial site creep testing system and its application[J].Chinese Journal of Rock Mechanics and Engineering,31(8):1636-1641.
Lian Z Y,Han G C,Kong X J.2001.Stability analysis of excavation by strength reduction FEM[J].Chinese Journal of Geotechnical Engineering,23(4):407-411.
Manzari M T,Nour M A.2000.Significance of soil dilatancy in slope stability analysis[J].Journal of Geotechnical and Geoenvironmental Engineering,126(1):75-80.
Maranini E,Brignoli M.1999.Creep behaviour of a weak rock.Experimental characterization[J].International Journal of Rock Mechanics and Mining Sciences,36(1):127-138.
Ruan H F,Luo Q,Meng W C,et al.2016.Analysis of time-effect characteristics of soil deformation and its classification based on direct shear test[J].Rock and Soil Mechanics,37(2):453-464.
Tan T K.1982.The mechanical problems for the long-term stability of underground galleries[J].Chinese Journal of Rock Mechanics and Engineering,1(1):1-20.
The National Standards Compilation Group of People's Repulic of China.2012.Code for design of building foundation[S].Beijing:China Architecture and Building Press.
Wang R B,Xu W Y,Meng Y D,et al.2014.Numerical analysis of longterm stability of left bank abutment high slope at JinpingⅠhydropower station[J].Chinese Journal of Rock Mechanics and Engineering,33(S1):3105-3113.
Yan C G,Li W,Zhao Z X,et al.2017.Impact analysis of creep movement of Zhengjiawan landslide to bridge across[J].Journal of Engineering Geology,25(2):416-423.
Yan G M.1986.A summary of the liaison bridges of Honshu and Shikoku[J].World Bridges,(2):1-17.
Yang J C.2016.Stability analysis of slope for gravity anchorage suspension bridge across Dadu River in Luding county[D].Chengdu:Southwest Jiaotong University.
Zhang G P,Zhou Z,Jiang Q H,et al.2017.Study on time-dependent deformation behavior and long-term stability of a 500 m-level super high slope[J].Chinese Journal of Underground Space and Engineering,13(6):1688-1694.
Zhang Q Y,Chen F,Yang W D,et al.2011.Field shear creep test and creep parameters inversion for dam zone rock mass of Dagangshan Hydropower Station[J].Rock and Soil Mechanics,32(9):2584-2590,2602.
Zhang Q Z,Shen M R,Ding W Q.2012.Study of mechanical properties and long-term strength of Jinping green schist[J].Chinese Journal of Rock Mechanics and Engineering,31(8):1642-1649.
Zhao H,Li W L,Wei J J,et al.2018.Model test study on toppling deformation evolution process of counter-tilt slope[J].Journal of Engineering Geology,26(3):749-757.
Zheng Y R,Zhao S Y.2004.Application of strength reduction FEM in soil and rock slope[J].Chinese Journal of Rock Mechanics and Engineering,23(19):3381-3388.
Zienkiewicz O C,Humpheson C,Lewis R W.1975.Associated and nonassociated visco plasticity and plasticity in soil mechanics[J].Géotechnique,25(4):671-689.
陈卫兵,郑颖人,冯夏庭,等.2008.考虑岩土体流变特性的强度折减法研究[J].岩土力学,29(1):101-105.
陈宗基.1982.地下巷道长期稳定性的力学问题[J].岩石力学与工程学报,1(1):7-26.
康文献,于怀昌,王玲玲,等.2016.三轴应力下水对粉砂质泥岩蠕变力学特性影响作用试验研究[J].工程地质学报,24(4):622-628.
李维树,周火明,钟作武,等.2012.岩体真三轴现场蠕变试验系统研制与应用[J].岩石力学与工程学报,31(8):1636-1641.
连镇营,韩国城,孔宪京.2001.强度折减有限元法研究开挖边坡的稳定性[J].岩土工程学报,23(4):407-411.
阮红风,罗强,孟伟超,等.2016.基于直剪试验的土体变形时间效应及状态类别分析[J].岩土力学,37(2):453-464.
王如宾,徐卫亚,孟永东,等.2014.锦屏一级水电站左岸坝肩高边坡长期稳定性数值分析[J].岩石力学与工程学报,33(S1):3105-3113.
严国敏.1986.日本本州四国联络桥综述[J].国外桥梁,(2):1-17.
晏长根,李为,赵珍祥,等.2017.郑家湾滑坡体蠕变对上跨桥梁的影响分析[J].工程地质学报,25(2):416-423.
杨锦程.2016.泸定大渡河悬索桥重力式锚碇边坡稳定性分析[D].成都:西南交通大学.
张公平,周钟,姜清辉,等.2017.500 m级超高边坡时效变形特征及长期稳定性研究[J].地下空间与工程学报,13(6):1688-1694.
张强勇,陈芳,杨文东,等.2011.大岗山坝区岩体现场剪切蠕变试验及参数反演[J].岩土力学,32(9):2584-2590,2602.
张清照,沈明荣,丁文其.2012.锦屏绿片岩力学特性及长期强度特性研究[J].岩石力学与工程学报,31(8):1642-1649.
赵华,李文龙,卫俊杰,等.2018.反倾边坡倾倒变形演化过程的模型试验研究[J].工程地质学报,26(3):749-757.
郑颖人,赵尚毅.2004.有限元强度折减法在土坡与岩坡中的应用[J].岩石力学与工程学报,23(19):3381-3388.
中华人民共和国行业标准编写组.2012.建筑地基基础设计规范(GB50007-2011)[S].北京:中国建筑工业出版社.