复杂软土盾构隧道纵向抗震分析

以天津Z2线盾构隧道工程为实例,基于ABAQUS有限元软件,建立三维梁-弹簧模型模拟盾构隧道,采用反应位移法对盾构隧道进行纵向抗震分析。根据盾构隧道接头实际情况,计算环间接头弹簧刚度。将地震作用下的自由场最大水平位移幅值,以简谐波的形式施加到盾构隧道轴向和横向。提出一种同时考虑轴向和横向水平地震动耦联效应的方法,通过调整轴向和横向(1/0.85或0.85/1)位移幅值的组合,求解了4种工况下盾构隧道的内力和接头张开量。通过对结果进行比较分析,得出一些对抗震设计具有参考价值的结论。

Longitudinal Seismic Analysis of Shield Tunnels in Complex Soft Soils

Taking the Tianjin Z2 line as an example, the longitudinal seismic analysis of the shield tunnel is carried out by the response deformation method. The ABAQUS finite element analysis software was used to establish a 3D beam-spring model for seismic analysis. According to the actual tunnel bolt connection, the ring-ring joint is simulated by springs. The maximum free-field horizontal displacement amplitude under earthquake is applied by sine-wave mode in the axial and lateral directions of the shield tunnel. By adjusting the displacement amplitude with 1/0.85 or 0.85/1 between the axial and lateral directions of the shield tunnel, the coupling effect between the axial and lateral directions are considered. The internal forces and joint opening of the shield tunnel for 4 coupling cases are obtained, and some conclusions valuable for engineering design are presented.