| 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2.134 m的钢管桩采用静压和锤击两种方法的安装过程。根据贯入过程中桩壁内外土体应力变化可知，静压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应力增加的数值较大，对周围土体影响范围也较大，在评估桩基承载力时，应适当考虑这种影响。 |
| 关键词: 有限元法 大变形 开口管桩 静压 锤击 贯入过程 应力变化 |
| DOI： |
| 分类号:TU473.1 |
| 基金项目:国家“973”计划资助项目(2014CB046800)；国家重大专项资助项目(2011ZX05056-002-01)；上海交通大学国
家重点实验室开放课题资助项目(1201) |
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| Numerical simulation analysis of driving methods affecting soil around pipe pile |
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XU Bao-zhao1, LI Sa1, XIA Ling-xiao2, DAI Xu1
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1.School of Civil Engineering, Tianjin University;2.Tianjin Housing Construction Co., Ltd.
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| Abstract: |
| The finite element method (FEM) is used to simulate the penetration process of a pipe pile and the stress of the soil mass around the pile changing with depth is simulated and analysed. Pile driving is a highly nonlinear process and large deformation problems can hardly be solved by a common method by contacting and meshing. Those problems can be solved by ALE meshing technology and a “zipper-type”method. In this paper, the penetration process of an open-ended pipe pile with diameter of 2.134 m 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 mass inside the pipe pile is higher than that of the soil mass outside according to the soil stress inside and outside the pile changing with the depth in the pile penetration process. So, soil plugging appears in the pile jacking more easily than that in the impact driving and squeezing effect is relatively obvious. By analyzing the stress changing with time at some points in the soil mass around the pipe pile during the driving, the increase of the stress of the soil mass around the impact pile is lager than that in the pile jacking, and so is the sphere of influence in the soil mass around the pipe pile. Therefere, this effect should be taken into consideration to evaluate the bearing capacity of the pipe pile. |
| Key words: finite element method large deformation open-ended piles pile jacking impact driving penetration process changes in stress |
