不同施工方法对管桩桩周土影响的有限元研究-水利水运工程学报.docVIP

不同施工方法对管桩桩周土影响的有限元研究 徐保照1(，李 飒1，夏玲晓2，戴 旭1 (1天津大学建筑工程学院，天津 300072； 2天津中房建设有限公司，天津 300000) 摘 要：利用有限元方法模拟钢管桩的贯入过程，研究贯入过程中桩周不同深度土体的应力变化过程。管桩贯入土体这一过程为高度非线性问题，通用的接触和网格划分方法难以解决大变形问题，通过采用ALE网格划分技术以及“zipper-type”方法解决了管桩贯入过程中的大变形和接触问题，运用ABAQUS模拟了直径D=2.134m的钢管桩采用静压和锤击这两种方法的安装过程。根据贯入过程中桩壁内外土体应力随深度变化关系，静力贯入过程中管内土水平应力明显高于管外土体的水平应力，更容易形成土塞，挤土效应也比较明显。通过对桩周土体中某点在安装过程中应力变化历程的分析，可以看到锤击安装方式在桩周土中造成的应力增加的数值较大，对周围土体影响范围也较大。在进行桩基承载力评估时，对于这种影响应该给予适当的考虑。 关键词：中图分类号：：Numerical investigation of the influence of the soil around the pipe pile with respect to the installation method XU Bao-zhao1, LI Sa1, XIA Ling-xiao2, DAI Xu1 （1.School of Civil Engineering, Tianjin University, Tianjin 300072, China；2. Housing Construction Co., Ltd. in Tianjin, Tianjin 300000, China） Abstract: Finite element method (FEM) is used to simulate the penetration process of pipe pile and the stress of the soil around pile changing with depth is investigated. Pile installation is a highly nonlinear process and large deformation problems can hardly be solved by common method of contact and meshing. Those problems can be solved by ALE meshing technology and zipper-type method. In this paper, the penetration process of an open-ended tubular pile with diameter D = 2.134m into clay soil is investigated by ABAQUS. And the following installation methods are considered: pile jacking and impact driving. The horizontal stress of the soil inside the tubular pile is higher than that of the soil outside according to the soil stress inside and outside the pile changing with depth in the pile penetration process. So, soil plugging appears in pile jacking more easily than that in impact driving and squeezing effect is relatively obvious. By analyzing the stress changing with time at some points in the soil around the pipe pile during the installation, the increase of the stress of the soil around the impact pile is lager than that in pile jacking, and so is the sphere of influence in the soil around the pipe pile. So this effect sho