摘要
对密贴下穿既有车站采用PBA工法施工新建车站的边桩桩端变形规律采用数值模拟方法进行了研究。结果表明:随着施工的进行,边桩桩端在上侧冠梁及外侧土压力的复杂荷载作用下向车站内侧偏移,其偏移速率变化过程是缓-快-缓;扣拱开挖阶段是边桩轴力变化最大的阶段,上部存在既有车站结构与上部不存在既有车站结构边桩由于扣拱开挖引起的轴力变化分别为其最大轴力的47.0%、55.3%;开挖车站上层阶段桩端变形较显著,此阶段上部存在既有车站结构与上部不存在既有车站结构边桩横向位移分别约为桩端最大位移的25.4%、33.3%;既有车站对位于其下部的边桩起一定保护作用,上部不存在既有车站结构边桩最大轴力与横向变形分别约为上部存在既有车站结构边桩的1.5~2.0倍、1.3倍。
A subway closely pass through the existing station,and the deformation law of side pile end of new station constructed by PBA(pile beam arch)method was studied by numerical simulation method. The results show that with the progress of construction,the pile end of side pile moves towards the inner side of the station under the complex load of upper crown beam and external earth pressure,and the change process of displacement rate is slow,fast and slow.The stage where the axial force of side pile changes most is the stage of arch lining excavation. The axial force changes of side piles with and without existing station structure in the upper part due to arch lining excavation are 47.0% and55.3% of their maximum axial force respectively. In the stage of excavating the upper layer of the station,the pile end deformation is significant. In this stage,the transverse displacement of the side pile with and without the existing station structure in the upper part is about 25.4% and 33.3% of the maximum displacement of the pile end respectively. The existing station has a certain protective effect on the side pile located at the lower part. The maximum axial force and transverse deformation of the side pile without the existing station structure at the upper part are about 1.5 ~ 2.0 times and 1.3 times that of the side pile with the existing station structure at the upper part.
作者
张嘉树
王海涛
张志伟
尤强
ZHANG Jiashu;WANG Haitao;ZHANG Zhiwei;YOU Qiang(School of Civil Engineering,Dalian Jiaotong University,Dalian Liaoning 116028,China;China Railway No.14 Group Corporation Tunnel Engineering Co.Ltd.,Ji’nan 250002,China)
出处
《铁道建筑》
北大核心
2021年第11期65-69,共5页
Railway Engineering
基金
辽宁省自然科学基金(2020-MS-271)
辽宁省教育厅科学研究计划(JDL2020014)
中铁十四局集团科技研究开发计划(2020QT03)。
关键词
地铁
桩端变形
数值模拟
现场监测
边桩轴力
PBA工法
ubway
pile end deformation
numerical simulation
on site monitoring
axial force of side pile
PBA method
