砂土中桩循环打入过程大变形数值模拟  

Numerical simulation of large deformation of piles in sand during cyclic penetration

作　　者：黄中原[1,2] 杨仲轩 郭宁[1,2] HUANG Zhongyuan;YANG Zhongxuan;GUO Ning(Computing Center for Geotechnical Engineering,College of Civil Engineering and Architecture,Zhejiang University,Hangzhou 310058,China;Engineering Research Center of Urban Underground Space Development of Zhejiang Province,Hangzhou 310058,China)

机构地区：[1]浙江大学岩土工程计算中心,浙江杭州310058 [2]浙江省城市地下空间开发工程技术研究中心,浙江杭州310058

出　　处：《岩土工程学报》2023年第2期411-418,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学国际合作重点项目(52020105003);国家杰出青年基金项目(51825803)。

摘　　要：深入认识桩打入过程引起的桩周土体应力场变化对准确计算打入桩的竖向承载力十分重要。在有限元分析软件ABAQUS中采用大变形任意拉格朗日-欧拉(ALE)方法以及状态相关莫尔-库仑砂土本构模型,模拟了室内标准模型槽试验,得到了桩循环打入过程中桩周砂土全阶段的应力变化规律,并重点分析了径向应力,验证了桩侧砂土应力水平的h/R效应(h为测点与桩尖竖向距离,向上为正;R为桩半径),获得了应力与桩尖和桩中心线相对位置的分布规律。数值模拟结果与室内模型试验实测结果较一致,验证了数值模拟方法的可靠性;有效补充了试验中难以测量的近桩侧区域的应力分布数据,可为打入桩的承载力设计理论和设计方法研究提供依据。It is extremely important to understand the stress conditions around the pile shaft during pile installation for accurately predicting its bearing capacity.The large-deformation arbitrary Lagrangian-Eulerian(ALE)finite element method in ABAQUS with the state-dependent Mohr-Coulomb sand model is employed to simulate the highly instrumented calibration chamber tests.The stress regimes developed at different penetration stages are obtained with a focus placed on the radial stress.The h/R effects of the stress in the surrounding soil are validated,along with the stress distribution varying with the relative distance with respective to the pile tip and pile centerline.The numerical simulation results are in good agreement with the experimental ones,indicating the robustness of the numerical model.The stress distribution obtained from the numerical analysis fills the blank of the stress data near pile shaft in experiments and is considered to be useful for improving the design methods for driven piles.

关 键 词：砂土 打入桩 数值模拟 循环打入 应力场 大变形 

分 类 号：TU435[建筑科学—岩土工程]