摘要
船坞基坑开挖由于工期和施工场地的限制,吊车桩基与支护结构施工需同步进行,基坑开挖过程中势必使邻近桩基产生附加变形和弯矩。针对此问题,应用有限元分析软件ABAQUS,采用修正剑桥模型,对船坞基坑开挖对邻近桩基影响进行三维有限元分析。得出如下结论:(1)基坑开挖对邻近桩基的影响,随着桩基与基坑的距离增大而减弱,当距离达到2倍开挖深度,基坑开挖对桩基的影响趋于稳定;桩身附加弯矩和变形增长率远远大于开挖深度增长率;(2)支护结构刚度和承台厚度增大,对控制邻近桩基附加变形作用明显,桩基附加位移及弯矩减小;(3)邻近桩基的桩径、桩基刚度越强及桩基桩长越大,桩身附加弯矩越大,附加位移越少,当桩长达到2倍开挖深度后附加位移趋于稳定;(4)随着桩基顶部的约束加强,桩基水平侧移减少,但桩基弯矩却随着约束的加强而增加。
Due to the limitation of schedule and construction site,crane pile foundation and supporting structure need to be synchronously constructed for dock pit. The dock pit excavation will certainly cause additional deformation and bending moment of the adjacent piles. A 3D finite element model was carried out by the software of ABAQUS.Some meaningful conclusions are obtained:( 1) The influence of pit excavation on adjacent piles decreases with the increases of the distance between adjacent pile and pit,when it reaches twice the depth of excavation,it tends to be stable; the increasing rate of additional bending moment and deformation is much greater than the excavation depth.( 2) The stiffness of supporting structure and thickness of cap have an obviously effect on controlling the additional deformation of neighboring pile. Increasing with the thickness and stiffness,the additional displacement and bending moment of adjacent pile decrease.( 3) The larger the diameter,stiffness and length of the pile,the larger the additional bending moment in piles was caused by pit excavation and the smaller additional displacement,when the pile length reaches twice the depth of excavation,additional displacement tends to be stable.( 4) With the constraint intensity of pile head increases,the lateral displacement of pile reduces,but bending moment increases.
出处
《地下空间与工程学报》
CSCD
北大核心
2016年第S1期246-253,274,共9页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51568006
41362016)
广西岩土力学与工程重点实验室资助课题(13-KF-02)
关键词
基坑开挖
邻近桩基
修正剑桥模型
三维有限元分析
pit excavation
adjacent piles
modified Cambridge model
three dimensional finite element analysis
