软土隧道开挖对群桩影响的三维分析  

Three dimensional analysis for the influence of tunnel excavation on pile foundations in soft soil

作　　者：秦会来 马敏 马少坤[2,3] QIN Hui-lai;MA Min;MA Shao-kun(China Construction First Group Construction&Development Co.,Ltd.,Beijing 100102,China;College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education,Nanning 530004,China)

机构地区：[1]中建一局集团建设发展有限公司,北京100102 [2]广西大学土木建筑工程学院,广西南宁530004 [3]工程防灾与结构安全教育部重点实验室,广西南宁530004

出　　处：《广西大学学报（自然科学版）》2020年第1期155-160,共6页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金资助项目(51678166,51508113,51779017);广西岩土力学与工程重点实验室开放基金(16-KF-01);道路结构与材料交通行业重点实验室(北京)开放基金课题(KF201303)

摘　　要：基于能较好地反映卸载条件下土体应力应变关系的HS模型,通过三维有限元模型对盾构隧道施工过程的合理再现,分析研究了上海等软土地区隧道施工对周边桩基础变形和内力的影响规律。基于数值仿真计算结果,重点探讨:1)隧道施工对群桩沉降变形的影响规律;2)隧道施工对不同位置桩身水平位移的影响规律及作用机理;3)隧道施工过程中桩端阻力以及桩身正负弯矩的发展演化规律。通过隧道施工对桩基变形与内力影响规律的揭示,可以发现,对于上海地区典型的软土地质条件,当隧道开挖面距参照面在1.5倍的隧道直径范围内时,隧道开挖对桩基沉降和承载力的影响最为显著。研究结论为软土地区隧道安全施工提供借鉴。Based on the HS model,which can reflect the stress-strain relationship of soils under unloading condition,the shield tunnel construction process in soft soil areas such as Shanghai was modelled by 3D finite element method,and the influence of tunnel construction on the deformation and internal forces of surrounding pile foundation was studied.On the basis of the numerical results,three key points were discussed.One was the influence of tunnel construction on the settlement and deformation of pile groups.The second was the influence of tunnel construction on the horizontal displacement of piles at different positions and also the action mechanism.The third was the evolution of the pile tip resistance and the positive and negative moments of piles during tunnel construction.By revealing the influence of tunnel construction on the deformation and internal forces of pile foundation,it could be found that for the typical soft soil geological conditions in Shanghai area,the influence of tunnel excavation on the settlement and bearing capacity of pile foundation were most significant when the distance between the excavation face and the reference face is within 1.5 times of the diameter of tunnel.The conclusion provides reference for safe construction of tunnels in soft soil areas.

关 键 词：隧道开挖 桩基 三维有限元 HS模型 

分 类 号：TU432[建筑科学—岩土工程]