沉管节段接头剪力键三维数值力学特性研究  

Research on Mechanical Characteristics of Segment Joint Shear Keys of Immersed Tunnel by Three Dimensional Numerical Method

作　　者：胡指南[1] 谢永利[1] 张宏光[1] 岳夏冰[1] 徐国平[2] 

机构地区：[1]长安大学公路学院,西安710064 [2]中交公路规划设计院有限公司,北京100088

出　　处：《地下空间与工程学报》2015年第2期429-434,共6页Chinese Journal of Underground Space and Engineering

基　　金：国家科技支撑计划项目(2011BAG07B01)

摘　　要：基于ANSYS有限元软件,构建沉管节段三维数值模型,在节段接头处定义接触单元,采用只受压的杆单元模拟橡胶支座,并定义其为双折线材料。调节沉管下部土层的弹性模量与泊松比,模拟沉管隧道在不均匀荷载及沉降条件下的纵向弯曲与扭转工况。通过分析节段接头剪力键的应力及剪力分布特征,研究沉管接头剪力键在上述工况下的受力特性。并将数值结果与大比例尺节段接头剪力键模型试验结果相对比。主要结论:两类工况中,竖向剪力键承担了几乎全部的竖向剪力,但对水平方向的抗剪基本不起作用,而水平剪力键在两类工况中都产生了水平剪力;扭转工况中,地层较软一侧竖向剪力键剪力较大;在剪力键端头角点及与节段衔接处局部应力较大。Based on the finite element software ANSYS, adopting contact elements at segment joints, utilizing double line elastic link elements, which can be only compressed, to simulate rubber pads, the three dimensional and numerical model of segmental immersed tunnel was constructed. The longitudinal bending and twisting working conditions of immersed tunnel under uneven load and settlement conditions could be simulated, by means of adjusting the elastic modulus and Poisson ratios of soil layers under the immersed tunnel. In addition, through analyzing characteristics of stresses and shearing forces on segment joint shear keys, the mechanical capacity of these keys was studied. Finally, the numerical results were compared with the results of large scale model test. The main conclusions are that, vertical shear keys which undertake most vertical shearing force have barely contribution to horizontal shearing resistance. However, the horizontal shear keys have horizontal shearing force in all these conditions. The shearing force of vertical shear keys on the side of soft layer is bigger than that on the side of hard layer. Furthermore, partial stresses on tips and connection areas of shear keys are significant.

关 键 词：港珠澳大桥 沉管隧道 节段接头 剪力键 数值分析 

分 类 号：U459.5[建筑科学—桥梁与隧道工程]