大直径变径桩竖向承载特性模型试验研究(Ⅰ)
|
摘要
变径桩在桥梁桩基和软土地基处理得到了一定程度的应用,对其承载特性和工作机制的研究十分必要。通过室内大型模型试验,对大直径变截面单桩的荷载与沉降关系、桩侧摩阻力分布形式、桩身内力和桩端、变截面处的破坏模式等问题进行了探讨,试验结果表明,在桩顶截面相同的情况下,变截面桩竖向承载特性受变截面比影响显著,变截面比越小,竖向极限承载力越小。模型试验P-S曲线不存在最优变截面比,变截面比设计受桩横向受力特性的控制。变截面处土体挤土效应的发挥是以牺牲桩顶位移为代价,在只有到达一定桩身位移时,才体现明显的挤土效应,使承载力提高。
Large diameter pile with variable cross-sections is applied to the region of bride engineering and foundation treatment.It is necessary to study the vertical bearing behaviors and working mechanism.The relation between vertical bearing capacity and settlement & distribution of the axial forces and skin friction along pile and failure mode of the pile are discussed based on laboratory test.According to the test,it is concluded that it is clear that the vertical bearing behaviors of the pile is affected by the ratio of variable diameters b value;the b is more smaller,the vertical bearing capacity is more smaller.It is proved that how to choose the b is controlled by the lateral bearing behaviors.The squeezing effect is not clear to improve the vertical bearing capacity unless the top displacement of the pile reaches a certain value.
Large diameter pile with variable cross-sections is applied to the region of bride engineering and foundation treatment.It is necessary to study the vertical bearing behaviors and working mechanism.The relation between vertical bearing capacity and settlement & distribution of the axial forces and skin friction along pile and failure mode of the pile are discussed based on laboratory test.According to the test,it is concluded that it is clear that the vertical bearing behaviors of the pile is affected by the ratio of variable diameters b value;the b is more smaller,the vertical bearing capacity is more smaller.It is proved that how to choose the b is controlled by the lateral bearing behaviors.The squeezing effect is not clear to improve the vertical bearing capacity unless the top displacement of the pile reaches a certain value.
引文
[1]王伯惠,上官兴.中国钻孔灌注桩新发展[M].北京:人民交通出版社,2001。
[2]易耀林,刘松玉,杜延军.路堤荷载作用下钉形搅拌桩复合地基附加应力扩撒特性[J].中国公路学报,2009,22(5):8-14.YI Yao-lin,LIU Song-yu,DU Yan-jun.Additional stressdistribution behavior of t-shaped deep mixed columncomposite foundation under embankment load[J].ChinaJournal of Highway and Transport,2009,22(5):8-14.
[3]易耀林,刘松玉,杜延军.路堤钉形搅拌桩复合地基沉降计算方法—广义桩体法[J].岩土工程学报,2009,31(8):1180-1188.YI Yao-lin,LIU Song-yu,DU Yan-jun.Generalizedcolumn method for calculation of settlement of t-shapeddeep mixed column composite foundation underembankment load[J].Chinese Journal of GeotechnicalEngineering,2009,31(8):1180-1188.
[4]易耀林,刘松玉,杜延军,等.变径水泥土搅拌桩单桩承载力试验研究[J].东南大学学报(自然科学版),2010,40(2):352-356.YI Yao-lin,LIU Song-yu,DU Yan-jun,et al.Field testson bearing capacity of single diameter-varied soil-cementdeep mixed column[J].Journal of Southeast University(Natural Science Edition),2010,40(2):352-356.
[5]卢成原,孟凡丽,王章杰,等.非饱和粉质粘土模型支盘桩试验研究[J].岩土工程学报,2004,26(4):522-525.LU Cheng-yuan,MENG Fan-li,WANG Zhang-jie,et al.Test of model piles with branches and plates inunsaturated silty clay[J].Chinese Journal ofGeotechnical Engineering,2004,26(4):522-525.
[6]钱德玲,李辉,卢文胜,等.变截面桩基础体系高层建筑结构的地震响应[J].岩土工程学报,2011,33(1):98--103.QIAN De-ling,LI Hui,LU Wen-sheng,et al.Seismicresponse of high-rise structures by different foundationsystems[J].Chinese Journal of GeotechnicalEngineering,2011,33(1):98-103.
[7]曹文贵,刘成学,赵明华.变截面桩的屈曲分析[J].湖南大学学报,2004,31(3):56-58.CAO Wen-gui,LIU Cheng-xue,ZHAO Ming-hua.Buckling analysis of the variable section piles[J].Journalof Hunan University(Natural Sciences).2004,31(3):56-58.
[8]刘杰,张可能.刚性承台下变截面柔性桩与地基相互作用的线性分析[J].岩土力学,2003,24(5):759-763.LIU Jie,ZHANG Ke-neng.Linear analysis of interactionof flexible piles with variable cross section and groundsoil under rigid pile cap[J].Rock and Soil Mechanics,2003,24(5):759-763.
[9]刘杰,张可能.柔性群桩承台下变截面角桩与地基相互作用的线性分析[J].水文地质工程地质,2003,1:13-17.LIU Jie,ZHANG Ke-neng.Linear analysis of interactionfor corner piles and soil under flexible grouped pilescap[J].Hydrogeology and Engineering Geology,2003,1:13-17.
[10]中国建筑科学研究院.JGJ79-2002《建筑地基处理技术规范》[S].北京:中国建筑工业出版社,2002.
[11]铁道第三勘测设计院.TB10002.5-2005《铁路桥涵地基和基础设计规范》[S].北京:中国铁道出版社,2005.
[2]易耀林,刘松玉,杜延军.路堤荷载作用下钉形搅拌桩复合地基附加应力扩撒特性[J].中国公路学报,2009,22(5):8-14.YI Yao-lin,LIU Song-yu,DU Yan-jun.Additional stressdistribution behavior of t-shaped deep mixed columncomposite foundation under embankment load[J].ChinaJournal of Highway and Transport,2009,22(5):8-14.
[3]易耀林,刘松玉,杜延军.路堤钉形搅拌桩复合地基沉降计算方法—广义桩体法[J].岩土工程学报,2009,31(8):1180-1188.YI Yao-lin,LIU Song-yu,DU Yan-jun.Generalizedcolumn method for calculation of settlement of t-shapeddeep mixed column composite foundation underembankment load[J].Chinese Journal of GeotechnicalEngineering,2009,31(8):1180-1188.
[4]易耀林,刘松玉,杜延军,等.变径水泥土搅拌桩单桩承载力试验研究[J].东南大学学报(自然科学版),2010,40(2):352-356.YI Yao-lin,LIU Song-yu,DU Yan-jun,et al.Field testson bearing capacity of single diameter-varied soil-cementdeep mixed column[J].Journal of Southeast University(Natural Science Edition),2010,40(2):352-356.
[5]卢成原,孟凡丽,王章杰,等.非饱和粉质粘土模型支盘桩试验研究[J].岩土工程学报,2004,26(4):522-525.LU Cheng-yuan,MENG Fan-li,WANG Zhang-jie,et al.Test of model piles with branches and plates inunsaturated silty clay[J].Chinese Journal ofGeotechnical Engineering,2004,26(4):522-525.
[6]钱德玲,李辉,卢文胜,等.变截面桩基础体系高层建筑结构的地震响应[J].岩土工程学报,2011,33(1):98--103.QIAN De-ling,LI Hui,LU Wen-sheng,et al.Seismicresponse of high-rise structures by different foundationsystems[J].Chinese Journal of GeotechnicalEngineering,2011,33(1):98-103.
[7]曹文贵,刘成学,赵明华.变截面桩的屈曲分析[J].湖南大学学报,2004,31(3):56-58.CAO Wen-gui,LIU Cheng-xue,ZHAO Ming-hua.Buckling analysis of the variable section piles[J].Journalof Hunan University(Natural Sciences).2004,31(3):56-58.
[8]刘杰,张可能.刚性承台下变截面柔性桩与地基相互作用的线性分析[J].岩土力学,2003,24(5):759-763.LIU Jie,ZHANG Ke-neng.Linear analysis of interactionof flexible piles with variable cross section and groundsoil under rigid pile cap[J].Rock and Soil Mechanics,2003,24(5):759-763.
[9]刘杰,张可能.柔性群桩承台下变截面角桩与地基相互作用的线性分析[J].水文地质工程地质,2003,1:13-17.LIU Jie,ZHANG Ke-neng.Linear analysis of interactionfor corner piles and soil under flexible grouped pilescap[J].Hydrogeology and Engineering Geology,2003,1:13-17.
[10]中国建筑科学研究院.JGJ79-2002《建筑地基处理技术规范》[S].北京:中国建筑工业出版社,2002.
[11]铁道第三勘测设计院.TB10002.5-2005《铁路桥涵地基和基础设计规范》[S].北京:中国铁道出版社,2005.
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