考虑接缝张开与变形影响的管片隧道抗震计算解析方法

摘要

A closed-form solution of seismic design of shield tunnel considering effect of local stress and deformation of segment joint is proposed.The deformation and rotation of shield tunnel's segment lining with joints is analyzed,assuming the 45 degree direction has the maximum deformation.Then the contact stress distribution of the interface at the joints are also formulated.Compared with models proposed by Sedarat in which joint is not incorporated,the bending moment distribution of the whole segment lining is found significantly changed,and localized concrete crush occurs at the joint interface.So,the segment joint should not be neglected during seismic design of segment tunnel.%基于管片间接触应力及张开变形的非线性及非连续性特性,提出了一种考虑管片间接缝影响的盾构隧道抗震计算解析方法.根据管片隧道在地震地层剪切变形作用下发生斜45 °方向的最不利椭圆化变形,基于管片刚体及接头动刚度假设推导此时接头的动力位移响应(转角、位移),进一步通过管片之间(接缝)的接触条件假设,得到了衬砌结构的内力及管片接缝的接触面应力分布以及螺栓内力.与不考虑接头的Sedarat、Hashash方法进行对比后发现,管片衬砌结构的弯矩分布形态发生了较大的变化,且在管片接缝处可能出现局部混凝土压碎,对抗震条件下的接缝防水安全及结构整体稳定性极为不利,因此,考虑管片接缝局部应力和变形的影响,对盾构隧道的抗震设计计算是十分必要的.