• 全国中文核心期刊
  • 中国科技核心期刊
  • 美国工程索引(EI)收录期刊
  • Scopus数据库收录期刊

刚性桩复合地基支承路堤稳定破坏机理的离心模型试验

郑刚, 李帅, 刁钰

郑刚, 李帅, 刁钰. 刚性桩复合地基支承路堤稳定破坏机理的离心模型试验[J]. 岩土工程学报, 2012, 34(11): 1977-1989.
引用本文: 郑刚, 李帅, 刁钰. 刚性桩复合地基支承路堤稳定破坏机理的离心模型试验[J]. 岩土工程学报, 2012, 34(11): 1977-1989.
ZHENG Gang, LI Shuai, DIAO Yu. Centrifugal model tests on failure mechanisms of embankments on soft ground reinforced by rigid piles[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(11): 1977-1989.
Citation: ZHENG Gang, LI Shuai, DIAO Yu. Centrifugal model tests on failure mechanisms of embankments on soft ground reinforced by rigid piles[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(11): 1977-1989.

刚性桩复合地基支承路堤稳定破坏机理的离心模型试验  English Version

基金项目: 国家自然科学基金项目(51078263)
详细信息
    作者简介:

    郑刚(1967– ),贵州贵阳人,男,博士,教授,博士生导师,从事土力学及岩土工程教学与科研工作。E-mail: zhenggang1967@163.com

  • 中图分类号: TU473.1

Centrifugal model tests on failure mechanisms of embankments on soft ground reinforced by rigid piles

  • 摘要: 对上软下硬成层土地基中刚性桩复合地基支承路堤,进行了单排桩和群桩条件下路堤稳定破坏机理的离心模型试验,研究了不同桩体抗弯刚度和强度,不同桩体加固位置,不同桩间距和桩端嵌入硬土层深度条件下桩体的受力与变形性状,破坏模式以及路堤的失稳破坏机理.离心机试验结果表明,不论是在单排桩还是群桩条件下,桩身最大弯矩作用点均产生于软硬土层交界面附近;在群桩条件下,桩体越靠近路堤中心桩身弯矩越小;当桩身抗弯刚度与强度较高,桩距较大且桩下端嵌入较硬土层足够深度时,可产生桩间土体沿桩的绕流甚至因产生绕流而导致路堤失稳破坏;当桩身抗弯刚度与强度较低时,在单排桩条件下,桩体会首先在软硬土层交界面处发生弯曲破坏,并可在路堤失稳前在桩身上部发生第二次弯曲破坏,而在群桩条件下,坡脚附近部分桩体首先在软硬土层交界面附近发生弯曲破坏,并可能伴随桩体受拉破坏而使桩断为上下两段,最后由于部分桩体发生整体倾覆破坏或者再次发生弯曲破坏而导致路堤发生失稳破坏;针对路堤具体的破坏情况有针对性地增大桩身抗弯强度,减小桩间距或增加桩端嵌入硬土层深度均可提高路堤的稳定性.
    Abstract: Centrifuge tests are carried out to study the embankment supported on the rigid pile composite ground. For all the test models, the upper layer of the ground is soft clay and the lower layer is stiff sand. The cases of using single-row piles and group piles are considered. The deformation behavior, load transfer and failure mechanisms of the piles and embankment are investigated with different pile bending stiffnesses and strengths, piles locations, pile spacings and embedded depth of pile toe into stiff stratum. The centrifuge tests show that in all the cases, the maximum bending moment of piles is located near the interface of soft and stiff strata. For the embankment on group piles, the closer to the embankment center the pile is, the smaller the bending moment is. When the piles have a high bending stiffness and strength, a large spacing, and a sufficient embedded depth into stiff stratum, soil may flow around the piles, which will lead to the overall failure of embankment. In contrast, for the single-row piles with a low bending stiffness and strength, the piles will fail firstly by bending failure mode at the interface of the soft and stiff strata, and then the secondary bending failure may occur at the upper part of the pile before the embankment failure. For the group piles with a low bending stiffness and strength, some piles near the embankment toe would also fail firstly by bending failure mode at the interface of the soft and stiff strata. Besides, the tensile failure may break the pile into two parts. In the final stage, the collapse failure or the secondary bending failure of the pile upper part will lead to the overall failure of embankment. According to the failure mechanisms of embankment, the embankment stability may be enhanced by the measures of increasing pile bending strength, decreasing pile spacing or increasing the embedded depth of pile toe into stiff stratum.
  • [1] JGJ 79—#2002 建筑地基处理技术规范[S]. 2002.
    JGJ 79—2002 Technical code for ground treatment of buildings[S]. 2002. (in Chinese))
    [2] JTG D30—#2004 公路路基设计规范[S]. 2004.
    JTG D30—2004 Specifications for design of highway subgrades[S]. 2004. (in Chinese))
    [3] JTS 147—#1—#2010 港口工程地基规范[S]. 2010.
    JTS 147—1—2010 Code for ground of port engineering[S]. 2010. (in Chinese))
    [4] TB 10001—#2005 铁路路基设计规范[S]. 2005.
    TB 10001—2005 Code for design on subgrade of railway[S]. 2005. (in Chinese))
    [5] 郑 刚, 刘 力, 韩 杰. 刚性桩加固软弱地基上路堤的稳定性问题(Ⅰ)——存在问题及单桩条件下的分析[J]. 岩土工程学报, 2010, 32(11): 1648-1657
    ZHENG Gang, LIU Li, HAN Jie. Stability of embankment on soft subgrade reinforced by rigid piles (Ⅰ) —Background and single pile analysis[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(11): 1648-1657. (in Chinese))
    [6] 郑 刚, 刘 力, 韩 杰. 刚性桩加固软弱地基上路堤的稳定性问题(Ⅱ)——群桩条件下的分析[J]. 岩土工程学报, 2010, 32(12): 1811-1820
    ZHENG Gang, LIU Li, HAN Jie. Stability of embankment on soft subgrade reinforced by rigid inclusions(Ⅱ)—group piles analysis[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(12): 1811-1820. (in Chinese))
    [7] HAN J, HUANG J, PORBAHA A. 2D Numerical modeling of a constructed geosynthetic-reinforced embankment over deep mixed columns[C]// ASCE GSP 131, Contemporary Issues in Foundation Engineering, 2005.
    [8] HUANG J, HAN J, PORBAHA A. Two and three-dimensional modeling of DM columns under embankments[C]// ASCE GeoCongress, 2006.
    [9] NAVIN M P, FILZ G M. Numerical stability analyses of embankments supported on deep mixed columns[C]// ASCE GSP 152, Ground Modification and Seismic Mitigation, 2006.
    [10] TERASHI M, TANAKA H, KITAZUME M. Extrusion failure of the ground improved by the deep mixing method[C]// Proceedings of the 7th Asian Regional Conference on Soil Mechanics and Foundation Engineering: Haifa, Israel, 1983: 313-318.
    [11] MIYAKE M, AKAMOTO H, WADA M. Deformation characteristics of ground improved by a group of treated soil[C]// Centrifuge 91. Rotterdam: Balkema, 1991:
    [12] HASHIZUME H, OKOCHI Y, DONG J,,et al. Study on the behavior of soft ground improved using deep mixing method[C]// Proc of the International Conference on Centrifuge 98, 1998: 851-856.
    [13] KITAZUME M, OKANO K, MIYAJIMA S. Centrifuge model tests on failure envelope of column type deep mixing method improved ground[J]. Soils and Foundations, 2000, 40(4): 43-55
    [14] KITAZUME M, MARUYAMA K. Collapse failure of group column type deep mixing improved ground under embankment[C]// Proc. of the International Conference on Deep Mixing, ASCE, 2005: 245-254
    [15] KITAZUME M, MARUYAMA K. External stability of group column type deep mixing improved ground under embankment loading[J]. Soils and Foundations, 2006, 46(3): 323-340
    [16] KITAZUME M, MARUYAMA K. Internal stability of group column type deep mixing improved ground under embankment loading[J]. Soils and Foundations, 2007, 47(3): 437-455
    [17] BROMS B B. Can lime/cement columns be used in Singapore and Southeast Asia?[R] 3rd GRC Lecture, Nanyang Technological University and NTU-PWD Geotechnical research Centre, 1999: 214
    [18] ZHENG G, LIU L. Numerical analysis of the pile lateral behavior and anti-slip mechanism of rigid pile supported embankments[C]// Advances in Ground Improvement: Research to practice in the United States and China-Proceedings of the 2009 US-China Workshop on Ground Improvement Technologies, 2009: 63-72.
    [19] 史旦达. 单调与循环加荷条件下砂土力学性质细观模拟[D]. 上海: 同济大学, 2007.
    SHI Dan-da. Micromechanical simulations of sand behavior under monotonic and cyclic loading[D]. Shanghai: Tongji University, 2007.
    [20] 聂守智. 用圆锥试验确定黏性土性质指标的新方法[J]. 岩土工程学报, 1984, 6(6): 18-29
    NIE Shou-zhi. A new approach to the determination of properties of the clayey soil by cone test[J]. Chinese Journal of Geotechnical Engineering, 1984, 6(6): 18-29. (in Chinese))
    [21] 聂守智. 用XC-1型袖珍触探仪测定液塑限的新方法[J]. 岩土工程学报, 1995, 17(5): 74-79
    NIE Shou-zhi. A new approach to the determination of the liquid limit and plastic limit of the soil by XC-1 pocket penetrometer[J]. Chinese Journal of Geotechnical Engineering, 1995, 17(5): 74-79. (in Chinese))
    [22] CECS54:93 袖珍贯入仪试验规程[S]. 1993.
    CECS54:93. Rules of pocket penetrometer test[S]. 1993. (in Chinese))
    [23] 10G409PHC管桩国家建筑标准图集规范[S]. 2010.
    10G409 Standard atlas specifications of national buildings for PHC pipe piles[S]. 2010. (in Chinese))
    [24] BUI Phu Doanh, 罗 强, 张 良, 等. 基于离心模型试验的高强度桩复合地基桩间距效应分析[J]. 铁道学报, 2009, 31(6): 69-75
    BUI Phu Doanh, LUO Qiang, ZHANG Liang,,et al. Analysis on pile spacing effect of composite foundation with high strength piles by centrifugal model test[J]. Journal of the China Railway Society, 2009, 31(6): 69-75. (in Chinese))
    [25] 黄 晶. 路堤荷载作用下CFG桩复合地基试验分析[D]. 成都: 西南交通大学, 2008.
    HUANG Jing. Experimental analysis of CFG pile composite foundation under embankment load[D]. Chengdu: Southwest Jiaotong University, 2008.
计量
  • 文章访问数:  1231
  • HTML全文浏览量:  0
  • PDF下载量:  585
  • 被引次数: 0
出版历程
  • 收稿日期:  2011-12-28
  • 发布日期:  2012-12-19

目录

    /

    返回文章
    返回