桩基负摩阻力研究中几个基本理论问题的探讨
|
摘要
桩基负摩阻力是个复杂的问题,由于其与土力学诸多领域的理论问题都有关联,所以对桩基负摩阻力的研究必然可加深对其他相关理论问题的认识。到目前为止,与桩基负摩阻力直接相关的诸多理论问题,都还未能得出令人满意的解答。针对这一现状,选取桩基负摩阻力研究中亟待解决的3个基本理论问题(影响桩基负摩阻力的主导因素、负摩阻力的实质以及负摩阻力的动力来源)加以研究。基于现场试验资料,从中分析得出影响桩基负摩阻力的2个主导因素,并据此从理论上推导出了桩基负摩阻力的实质,即桩基负摩阻力可看作是桩周有效沉降土体的重力在土体抗剪强度的转化之下而产生的一种作用于桩身的力,最后建立一个说明桩基负摩阻力动力来源的理论模型。
Investigation on negative skin friction(NSF) is complicated in the effort to connect with some other theoretical problems in soil mechanics field.Consequently,it could help to advance our understanding on these problems in soil mechanics field in the NSF.However,some theoretical problems of the NSF are not interpreted reasonably.In order to understand the problems three important theoretical problems of the NSF:the dominant influencing factors of the NSF,the relation between NSF,and weight of the soil mass around pile and the power sources of the NSF are analyzed.Based on the in-situ data and theoretical analysis,two dominating factors,i.e.,the effective weight of the soil mass above certain depth and the settlement of the soil mass around the pile at the certain depth,are discussed.Then on the basis of the two above-mentioned dominating factors,the NSF could be regarded as a force acted on pile due to the lost gravitational potential energy of the subsiding soil mass,and as the force limited by shear strength of the soil mass.Finally,a theoretical model of power sources of NSF to illuminate the results is established.
Investigation on negative skin friction(NSF) is complicated in the effort to connect with some other theoretical problems in soil mechanics field.Consequently,it could help to advance our understanding on these problems in soil mechanics field in the NSF.However,some theoretical problems of the NSF are not interpreted reasonably.In order to understand the problems three important theoretical problems of the NSF:the dominant influencing factors of the NSF,the relation between NSF,and weight of the soil mass around pile and the power sources of the NSF are analyzed.Based on the in-situ data and theoretical analysis,two dominating factors,i.e.,the effective weight of the soil mass above certain depth and the settlement of the soil mass around the pile at the certain depth,are discussed.Then on the basis of the two above-mentioned dominating factors,the NSF could be regarded as a force acted on pile due to the lost gravitational potential energy of the subsiding soil mass,and as the force limited by shear strength of the soil mass.Finally,a theoretical model of power sources of NSF to illuminate the results is established.
引文
[1]何颐华,闵连太.湿陷性黄土地基桩的负摩擦力问题[J].建筑结构学报,1982,3(6):69–77.(He Yihua,Min Liantai.Problems on negative friction of pile foundation in collapsible loess region[J].Journal of Building Structures,1982,3(6):69–77.(in Chinese))
[2]Johannessen I J,Bjerrum L.Measurements of a steel pile to rock due to settlements of the surrounding clay[A].In:Proc.the 6th ICSMFE,Montreal[C].Toronto,Canada:University of Toronto Press,1965.261–264.
[3]Poulos H G,Mattes N S.The analysis of downdrag in end-bearing piles[A].In:the Proc.the 7th ICSMFE,Mexico City[C].Mexico:Sociedad Mexicana de Mecanica de Suelos,1969.203–209.
[4]Poulos H G,Davis E H.The development of negative frication with time in end-bearing piles[J].Aust.Geomechs,1972,62(1):11–20.
[5]Walker L K,Darvall P.Dragdown on coated and uncoated piles[A].In:Proc.the 8th ICSMFE,Moscow[C].Rotterdam:A.A.Balkema,1973.257–262.
[6]Small J C.Finite element analysis of downdrag on piles[A].In:Proc.the Sixth International Conference on Numerical Methods in Geomechanics,Innsbruck[C].Rotterdam:A.A.Balkema,1988.1 109–1 114.
[7]Lee C J,Bolton M D,Al-Tabbaa A.Numerical modelling of group effects on the distribution of dragloads in pile foundations[J].Geotechnique,2002,52(2):325–335.
[8]赵锡宏,张启辉,张保良.承受负摩擦力的桩基沉降计算的迭代法[J].岩土力学,1999,20(2):17–21.(Zhao Xihong,Zhang Qihui,Zhang Baoliang.Iterative method for calculating the settlement of pile foundation with negative friction[J].Rock and Soil Mechanics,1999,20(2):17–21.(in Chinese))
[9]王建华,陆建飞,沈为平.Biot固结理论在单桩负摩擦研究中的应用[J].岩土工程学报,2000,22(5):590–593.(Wang Jianhua,Lu Jianfei,Shen Weiping.The application of Biot consolidation theory to the negative friction problem of single pile[J].Chinese Journal of Geotechnical Engineering,2000,22(5):590–593.(in Chinese))
[10]惠焕利.桩基设计中负摩阻力问题的探讨[J].陕西水力发电,2000,16(2):26–29.(Hui Huanli.Discussion of negative skin friction on pile[J].Journal of Shaanxi Water Power,2000,16(2):26–29.(in Chinese))
[11]孙军杰.黄土地基沉降时桩的负摩阻力计算方法研究[硕士学位论文][D].兰州:中国地震局兰州地震研究所,2004.(Sun Junjie.A study on computing method of negative skin friction on pile in subsiding loess ground[M.S.Thesis][D].Lanzhou:Lanzhou Institute of Seismology,China Earthquake Administration,2004.(in Chinese))
[12]黄雪峰,孙树勋,徐毅明,等.大厚度自重湿陷性黄土场地人工成孔灌注桩负摩阻力沿桩身传递特征[A].见:韩丽霞,莫庸编.甘肃省土木建筑学会建会五十周年[C].[s.l.]:[s.n.],2002.144–150.(Huang Xuefeng,Sun Shuxun,Xu Yiming,et al.Characteristic of negative skin friction on borehole cast-in-place concrete pile in heavy thickness self-weight collapsible loess ground[A].In:Han Lixia,Mo Yong ed.The 50th Anniversary of the Founding of Gansu Academy of Civil Construction[C].[s.l.]:[s.n.],2002.144–150.(in Chinese))
[2]Johannessen I J,Bjerrum L.Measurements of a steel pile to rock due to settlements of the surrounding clay[A].In:Proc.the 6th ICSMFE,Montreal[C].Toronto,Canada:University of Toronto Press,1965.261–264.
[3]Poulos H G,Mattes N S.The analysis of downdrag in end-bearing piles[A].In:the Proc.the 7th ICSMFE,Mexico City[C].Mexico:Sociedad Mexicana de Mecanica de Suelos,1969.203–209.
[4]Poulos H G,Davis E H.The development of negative frication with time in end-bearing piles[J].Aust.Geomechs,1972,62(1):11–20.
[5]Walker L K,Darvall P.Dragdown on coated and uncoated piles[A].In:Proc.the 8th ICSMFE,Moscow[C].Rotterdam:A.A.Balkema,1973.257–262.
[6]Small J C.Finite element analysis of downdrag on piles[A].In:Proc.the Sixth International Conference on Numerical Methods in Geomechanics,Innsbruck[C].Rotterdam:A.A.Balkema,1988.1 109–1 114.
[7]Lee C J,Bolton M D,Al-Tabbaa A.Numerical modelling of group effects on the distribution of dragloads in pile foundations[J].Geotechnique,2002,52(2):325–335.
[8]赵锡宏,张启辉,张保良.承受负摩擦力的桩基沉降计算的迭代法[J].岩土力学,1999,20(2):17–21.(Zhao Xihong,Zhang Qihui,Zhang Baoliang.Iterative method for calculating the settlement of pile foundation with negative friction[J].Rock and Soil Mechanics,1999,20(2):17–21.(in Chinese))
[9]王建华,陆建飞,沈为平.Biot固结理论在单桩负摩擦研究中的应用[J].岩土工程学报,2000,22(5):590–593.(Wang Jianhua,Lu Jianfei,Shen Weiping.The application of Biot consolidation theory to the negative friction problem of single pile[J].Chinese Journal of Geotechnical Engineering,2000,22(5):590–593.(in Chinese))
[10]惠焕利.桩基设计中负摩阻力问题的探讨[J].陕西水力发电,2000,16(2):26–29.(Hui Huanli.Discussion of negative skin friction on pile[J].Journal of Shaanxi Water Power,2000,16(2):26–29.(in Chinese))
[11]孙军杰.黄土地基沉降时桩的负摩阻力计算方法研究[硕士学位论文][D].兰州:中国地震局兰州地震研究所,2004.(Sun Junjie.A study on computing method of negative skin friction on pile in subsiding loess ground[M.S.Thesis][D].Lanzhou:Lanzhou Institute of Seismology,China Earthquake Administration,2004.(in Chinese))
[12]黄雪峰,孙树勋,徐毅明,等.大厚度自重湿陷性黄土场地人工成孔灌注桩负摩阻力沿桩身传递特征[A].见:韩丽霞,莫庸编.甘肃省土木建筑学会建会五十周年[C].[s.l.]:[s.n.],2002.144–150.(Huang Xuefeng,Sun Shuxun,Xu Yiming,et al.Characteristic of negative skin friction on borehole cast-in-place concrete pile in heavy thickness self-weight collapsible loess ground[A].In:Han Lixia,Mo Yong ed.The 50th Anniversary of the Founding of Gansu Academy of Civil Construction[C].[s.l.]:[s.n.],2002.144–150.(in Chinese))
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心