地基沉降对沉管隧道节段接头剪力键力学性能影响研究  

Influence of foundation settlement on mechanical performance of shear keys of segment joints in immersed tube tunnels

作　　者：刘禹阳 谢永利[1] 来弘鹏[1] 张宏光[1] 

机构地区：[1]长安大学桥梁与隧道陕西省重点实验室,陕西西安710064

出　　处：《岩土工程学报》2015年第12期2235-2244,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家科技支撑计划项目(2011BAG07B00);国家自然科学基金项目(51008029;51378071);陕西省科学技术研究发展计划项目(2014KJXX-53);陕西省自然科学基金项目(2013JQ7030)

摘　　要：为了更全面地了解地基沉降对沉管隧道节段接头剪力键力学性能影响情况,以港珠澳沉管隧道工程为背景,系统开展了两种不同沉降工况下几何相似比为1∶4.69的大型模型试验,并利用有限元对实际沉管节段进行数值模拟,研究了地基沉降下节段接头剪力键力学性状和剪力的分布情况。试验结果表明:剪力键应力变化主要影响因素为地基沉降,接头内剪力键的空间组合对应力影响不明显;地基沉降过程中,水平剪力键应力值相对较小;中墙剪力键下部端角先于侧墙剪力键下部端角与剪力键槽挤压,且前者量值大于后者,中墙剪力键下部端角最先受压破坏;接头内剪力键根部剪力分布与剪力键布设方向关系紧密,节段横断面一侧地基下沉对另一侧节段产生横拉效应;同时提出了接头内最大剪力与地基沉降关系方程和各竖向剪力键的竖向剪力承担比例。In order to have a more comprehensive understanding of the influence of foundation settlement on mechanical performance of shear keys of segment joints in immersed tube tunnels, based on the5 immersed tube tunnel project of Hong Kong-Zhuhai-Macao Bridge, large-scare model tests with geometric similarity ratio of 1∶4.69 under two different settlement working conditions are systematically carried out. A finite element numerical simulation on segments of the real immersed tube tunnel is made simultaneously. The mechanical properties of shear key of segment joints and the distribution of shear force are studied. The experimental results show that：（1） The dominant influence on change of stress in the shear keys is induced by the foundation settlement.（2） In the process of foundation settlement, the stress value of the horizontal shear keys is relatively small;（3） The lower end of the angle of shear keys in middle walls is compressed earlier than the same position in side walls, and the former is larger than the latter one in the value of stress, so the shear keys in the middle wall is crushed firstly;（4） The deformation trend of vertical shear keys is that the lower part is being compressed and the upper part is moving apart with shear key trough, the shear force distribution of the roots of shear keys among a joint relates closely with the setting position of shear keys, and in a cross section the foundation subsidence at one side leads to horizontal pull effect on the linings of immersed tube at the other side;（5） The equations for the maximum shear force and foundation settlement in a joint are put forward as well as the vertical shear ratio among the vertical shear force in the joint.

关 键 词：沉管隧道 大比例尺物理模型试验 有限元 地基沉降 剪力 

分 类 号：TU433[建筑科学—岩土工程]