考虑错台条件的盾构隧道抗震性能分析

Seismic Performance Analysis of Shield Tunnel Considering Segment Misalignment

研究目的:管片错台是盾构隧道最为常见的质量问题之一,管片错台直接影响管片的受力,从而影响隧道整体抗震性能,可见管片错台对盾构隧道抗震性能的影响值得关注。目前相关研究较少,缺乏合理考虑错台的方法。针对该问题,本文提出一种考虑错台的方法,并借助数值方法探讨盾构隧道管片错台量及错台部位对其地震响应的影响。研究结论:(1)结构内力方面,盾构隧道在发生初始错台后内力会出现增大,其中剪力的增幅最为明显;(2)结构变形方面,初始错台会增大隧道在地震作用下的环缝错台量;(3)结构应力方面,隧道应力随着环缝错台量的增大而显著增加,错台特别是初始错台对隧道抗震性能极为不利;(4)本研究成果可为盾构隧道的初步设计以及运营期间抗震性能评价提供参考。

Research purposes: Segment misalignment is one of the most common quality problems of shield tunnels. Segment misalignment directly affects the stress of segments, thereby affecting the overall seismic performance of the tunnel. The influence of segment misalignment on the seismic performance of shield tunnels is worthy of attention. At present, there are few relevant studies, and there is a lack of reasonable method to consider the misalignment. In view of this problem, this paper proposes a method to consider the misalignment, and discusses the influence of the misalignment amount and position of shield tunnel segment on its seismic response by numerical method.Research conclusions:(1) In terms of structural internal force, the internal force of shield tunnel will increase after the initial dislocation, and the increase of shear force is the most obvious.(2) In terms of structural deformation, the initial misaligned will increase the amount of misalignment at the circumferential joints of the tunnel under seismic action.(3) In terms of structural stress, the tunnel stress increases significantly with the increase of the number of misaligned joints, and the misaligned joints, especially the initial misaligned joints, are extremely unfavorable to the seismic performance of the tunnel.( 4) The research results can provide reference for the preliminary design of shield tunnels and the seismic performance evaluation during operation.