PBA法扩挖大直径盾构隧道修建地铁车站时结构关键节点的受力分析  

Mechanical Behavior of Critical Joints in Enlarging Large Diameter Shield Tunnel by PBA Method to Build Metro Station

作　　者：王芳[1] 汪挺 贺少辉[1] 刘军[3] 邹彪[4] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]北京市政建设集团有限责任公司,北京100045 [3]北京建筑大学土木与交通工程学院,北京100044 [4]北京市市政工程设计研究总院,北京100082

出　　处：《中国铁道科学》2013年第5期54-62,共9页China Railway Science

基　　金：北京市自然科学基金资助项目(KZ201310016016)

摘　　要：北京地铁14号线东风北桥站至阜通东站区段隧道采用土压平衡盾构修建,并采用PBA(PileBeam-Arch)法小规模暗挖拓展形成地铁车站。将扩挖过程中车站结构的关键节点分为管片接头、K管片分块连接处、纵梁与管片连接处以及主拱初支与K管片连接处4类。根据关键节点的结构形式,采用三维非连续接触模型模拟施工过程,分析关键节点的变形和内力。结果表明:管片接头和K管片分块连接处变形满足要求;施工过程对管片内力重分布影响很大,部分连接螺栓超出抗拉强度;顶纵梁与顶管片连接处在对称开挖情况下未产生相对滑移,但有略微分离现象,造成顶纵梁抗剪键超出抗拉强度;底纵梁和底管片连接处未出现相对滑移和分离;主拱初支与K管片连接处的焊缝强度满足要求。由此可见,本工程中车站结构基本处于稳定状态,只有局部需要加强。The section tunnel from Dongfengbeiqiao Station to Futongdong Station of Beijing Metro Line 14 was constructed by earth pressure balance shield, and the shield tunnel will be enlarged in small-scale by PBA （Pile--Beam-Arch） method to form small metro station. The critical joints of station structure during the enlarging process have four categories. They are segment joints, blocks connection of key segment, connection between longitudinal beams and segments as well as the joints of main arch primary supports and key segments. According to the structural styles of critical joints, the three-dimensional discontinuous contact model is used to simulate the construction process, and the deformation and internal force of criti- cal joints are studied. The results show that the deformation of segment joints and blocks connection of key segment meets the requirement. The construction process greatly influences the redistribution of structural internal force so some bolts exceed tensile strength. The connection of top longitudinal beam and top seg- ment doesn＇t slip relatively but separates slightly in the case of symmetrical excavation. The resisting shear bolts of top longitudinal beam exceed tensile strength. The connection of bottom longitudinal beam and bottom segment doesn＇t slip and separate relatively, and the weld seams of joints of main arch primary sup- ports and key segments meet requirement. Thus the station structure is basically steady in this project, only parts need to be strengthened.

关 键 词：盾构隧道 地铁车站 PBA法扩挖 车站结构 节点受力 

分 类 号：U451[建筑科学—桥梁与隧道工程] U231.4[交通运输工程—道路与铁道工程]