双层隧道内部结构对隧道纵向力学性能的影响

Influence of Internal Structure of Double Deck Tunnel on Longitudinal Mechanical Properties of Tunnel

以武汉两湖隧道(东湖段)工程为背景,通过考虑双层隧道内部结构的盾构隧道三维数值计算模型对双层隧道纵向力学性能进行研究。结果表明:双层隧道内部结构能够显著提高盾构隧道的纵向刚度,错缝和通缝拼装形式隧道考虑双层隧道内部结构后的纵向刚度有效率分别增加了12.5%~30.0%和17.5%~40.0%;双层隧道内部结构能够起到显著分担荷载的作用,错缝和通缝拼装形式隧道的管片环各部位Mises应力分别减小了27.2%~74.9%和12.2%~40.0%;管片的拼装形式对内部结构的竖向位移有影响;双层隧道内部结构受到弯扭作用,在纵向上的变形与梁类似;错缝和通缝拼装隧道的双层隧道内部结构中间4块内部结构侧墙连接处均有应力集中现象发生。

Taking Donghu section of Wuhan Lianghu tunnel project as the background,the longitudinal mechanical properties of the double deck tunnel were studied by considering the shield tunnel three-dimensional numerical calculation model of double deck tunnel internal structure.The results show that the longitudinal stiffness of shield tunnel can be improved significantly by the internal structure of double deck tunnel.The effective efficiency of longitudinal stiffness of staggered joint and through joint assembly tunnels is increased by 12.5%~30.0%and 17.5%~40.0%respectively after considering the internal structure of double deck tunnel.The internal structure of double deck tunnel can share the load significantly,and Mises stress in every segment part of the staggered joint and through joint assembly tunnels is decreased by 27.2%~74.9%and 12.2%~40.0%respectively.The vertical displacement of the internal structure is affected by the segment assembly form.The internal structure of double deck tunnel is subjected to bending and torsion,and its longitudinal deformation is similar with that of beam.There is the stress concentration phenomenon at the joint of the side walls in the middle four internal structure of double deck tunnel internal structure for staggered joint and through joint assembly tunnel.