摘要
为研究沉管隧道接头各组剪力键在竖向剪切过程中的剪力分配及随外荷载的变化规律,展开了沉管隧道管节接头的竖向剪切试验。试验根据之前沉管隧道试验经验、场地条件、加载能力以及测量手段,设计试验沉管管节接头模型,其中包括管节尺寸及配筋、竖向剪力键构造及GINA橡胶止水带等等。针对此试验的加载情况,自主研发了一种多维多向自平衡式加载反力装置。该装置不受场地限制,可多方向进行加载,也不需要地锚、剪力墙等限位装置便可自平衡。试验时首先在管节轴向施加正常运营时的最低轴压荷载,然后在接头位置垂直管节轴向逐级施加竖向剪切荷载,以测试每级竖向荷载下接头竖向相对位移、钢剪力键齿应变。试验结果表明:管节接头各组剪力键竖向位移不相同,右侧竖向位移大于左侧;同组剪力键相对键齿上的剪切应力分布不对称,键齿间接触面发生了6 mm水平向偏移。各组剪力键分担的剪切荷载与其钢键齿和齿间橡胶支座的刚度有关,并非设计时预想的平均分配。
In order to study the shear load distribution during the vertical shearing processes of all the shear-key groups for the joint of immersed-tube tunnel and the law of their changes along with external load,a vertical shear experiment for the joint of immersed-tube tunnel is carried out.In accordance with the experience from the previous experiment made on the immersed-tube tunnel,the site condition,the loading capacity and the measuring means,a model for the tube-segment joint of the experimental immersed tube is designed,which includes the dimension and reinforcement of the tube-segment,the structure of vertical shear-key,rubber gasket,etc.For the loading condition of the experiment,a reversed force device for multi-dimensional and multi-directional self-balancing loading is independently developed.The device is not limited by the site condition and can make multi-directional loading,thus can be self-balanced without any caging devices,i.e.ground-anchor,shearing wall,etc.During the experiment,the minimum axial compressive load is firstly applied on the tube-segment in the axial direction according to the operation condition,and then the vertical shear loading perpendicular to the axial direction of the tube-segment is applied step by step for testing the vertical relative displacement and the strain of the steel shear-key tooth of the joint under the vertical loads of every steps.The experiment result shows that the vertical displacements of all the shear-key groups for the tube-segment are different and the vertical displacement on the right side is larger than that of the left side,while the shear stress distributions of the shear-keys in the same group are asymmetric with the horizontal offset of 6 mm of the interface among the key teeth.Moreover,the shear load shared by all the shear-key groups is related to the stiffness of both the steel key tooth and the rubber support seat among the key teeth,which is not the average distribution expected in the design.
作者
袁勇
罗健珲
禹海涛
陈伟乐
YUAN Yong;LUO Jianhui;YU Haitao;CHEN Weile(State Key Laboratory of Disaster Reduction of Civil Engineering,Tongji University,Shanghai 200092,China;Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of the Ministry of Education,Tongji University,Shanghai 200092,China;Administration Center of Shenzhen-Zhongshan Passageway,Zhongshan 528451,Guangdong,China)
出处
《水利水电技术》
北大核心
2020年第5期17-25,共9页
Water Resources and Hydropower Engineering
基金
国家重点研发计划项目(2018YFC0809602,2017YFC1500703)
国家自然科学基金项目(51778487,51678438)。
关键词
沉管隧道
接头剪切试验
钢剪力键
剪力分配
immersed-tube tunnel
shear experiment of joint
steel shear key
distribution of shear load
