刚性桩复合地基边桩效应的模型试验研究  

ExperimentalModel TestonBoundaryPileEffectofRigidPileCompositeFoundation

作　　者：其米旺姆 李守德[1,2] QIMI Wangmu;LI Shoude(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;Jiangsu Research Center for Geomechanical Engineering Technology,Hohai University,Nanjing 210098,China;Tibet Engineering Technology Center of Civil,Water Conservancy and Electric,Tibet Agriculture and Animal Husbandry University,Nyingchi 860000,Tibet China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,南京210098 [2]河海大学江苏省岩土工程技术研究中心,南京210098 [3]西藏农牧学院西藏土木水利电力工程技术研究中心重点实验室,西藏林芝860000

出　　处：《河南科学》2019年第2期230-235,共6页Henan Science

基　　金：国家自然科学基金(51778211);江苏省自然科学基金(BK20171434);西藏大学农牧学院雪域英才计划项目(2015XYC03)

摘　　要：刚性桩复合地基的边缘区域存在着边桩效应,这与刚性桩复合地基的失稳破坏存在着直接联系,对复合地基的承载能力和工作性状具有重要的影响.基于模型试验,通过对桩体轴力、桩侧摩阻力和桩土应力的分析,对刚性桩复合地基的边桩效应进行了系统的研究.研究表明:桩身最大轴力点位置大约在1/3桩长处,也与桩侧摩阻力中性点的位置基本相同;在相同荷载作用下,内桩分担的轴力比边桩大,且受力比较均匀;桩土应力的分布规律验证了刚性桩复合地基中土拱效应的产生,且内桩的桩土应力比大于边桩,体现了内桩相对于边桩在荷载传递中发挥了更为明显的分担作用.研究结果对于具体的工程应用具有一定的指导意义.The boundary pile effect exists at the edge region of the rigid pile composite foundation,which is directly related to the instability failure of rigid pile composite foundation,and has an important influence on its bearing capacity and working characteristics. Based on the model test,this paper makes a systematic study on the boundary pile effect by analyzing the axial forces and skin frictions of the rigid pile and the pile-soil stresses. The results of the model test show that the maximum axial force of the piles occurs at approximately 1/3 of the length,and is similar to the distribution of the skin friction;under the same load,the axial force of the internal piles is larger than the boundary piles,and the stress is more uniform;the distribution of pile-soil stresses verifies the occurrence of soil arching effect in the rigid pile composite foundation,and the pile soil stress ratio of the internal piles is larger than that of the boundary piles,this indicates that the internal piles play a more obvious role in the load transfer relative to the boundary piles. The research results may provide a reference for the actual engineering applications.

关 键 词：刚性桩复合地基 边桩效应 模型试验 桩身轴力 桩侧摩阻力 

分 类 号：TU47[建筑科学—结构工程]