软土地区超大直径盾构隧道-竖井连接端部地震动力响应  

Seismic Dynamic Response of Ultra⁃large Diameter Shield Tunnel⁃Vertical Shaft Connection End in Soft Soil Areas

作　　者：李佳琪 LI Jiaqi(China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]中国铁路设计集团有限公司,天津300308

出　　处：《铁道建筑》2025年第1期121-126,共6页Railway Engineering

基　　金：中国铁路设计集团有限公司科技开发课题(2023BTJ13,2021B240603)。

摘　　要：盾构隧道-竖井连接端部是盾构隧道抗震设防的薄弱部位。为研究软土地区超大直径盾构隧道-竖井连接端部地震动力响应,以长江河口区域某高速铁路隧道工程为背景,建立盾构隧道-竖井-土体三维整体计算模型,采用动力时程分析法,研究在“两等级,三方向”不同地震波激振作用下盾构隧道-竖井连接端部的地震响应情况,对竖井结构相对变形和层间位移角、盾构隧道的横向变形和纵向变形,管片张开量及端部连接处结构内力的动力响应进行分析。结果表明:在设防地震(50年超越概率10%)和罕遇地震(100年超越概率2%)作用下,盾构隧道-竖井结构整体能够保持一定的稳定性和安全性。地震作用的激振方向对结构内力分布和变形影响显著,整体影响规律为45°方向> X方向> Y方向。地震作用下,盾构隧道横断面与竖轴共轭45°的位置受力最不利。盾构隧道纵向端部效应影响范围主要与自身几何尺寸相关,端部效应影响范围约为0.3D~0.5D(D为管片外径)。端部连接处结构容易出现受拉损伤破坏,管片环缝张开量明显大于纵缝张开量,盾构管片的纵向连接应予以重点关注。成果可为类似工程的抗震性能分析和结构抗震设计提供参考。The end of the shield tunnel vertical shaft connection is the weak point in the seismic fortification of shield tunnels.In order to study the seismic dynamic response of the connection end of a ultra-large diameter shield tunnel-vertical shaft in soft soil areas,a three-dimensional integrated calculation model of shield tunnel-vertical shaft-soil was established based on a high speed railway tunnel project in a certain city in the Yangtze River estuary area.The dynamic time history analysis method was used to study the seismic response of the shield tunnel vertical shaft connection end under the excitation of seismic waves in different working conditions of“two levels,three directions”.The relative deformation and inter story displacement angle of the vertical shaft structure,the lateral and longitudinal deformation force characteristics of the shield tunnel,the opening amount of the shield pipe segment and the dynamic response of the internal forces of the end connection structure were analyzed.The results show that under the action of resistance earthquake(50 years probability of surpassing is 10%)and rare earthquake(100 years probability of surpassing is 2%),the shield tunnel vertical shaft structure can maintain a certain degree of stability and safety as a whole.The excitation direction has a significant impact on the distribution and deformation of internal forces in structures,with an overall impact pattern of 45°direction>X direction>Y direction.Under earthquake action,the position where the crosssection of the shield tunnel is conjugate with the vertical axis at 45°is the most unfavorable for stress.The range of influence of the longitudinal end effect of the shield tunnel is mainly related to the geometric size characteristics of its own structure.The range of influence of the end effect is about 0.3D~0.5D(D is the outer diameter of the segment).The structure at the end connection is prone to tensile damage,and the opening of the ring joint is significantly greater than that of the longitudinal jo

关 键 词：铁路隧道 软土地区 盾构隧道-竖井 激振方向 时程分析 动力响应 

分 类 号：U451.9[建筑科学—桥梁与隧道工程] U452.28[交通运输工程—道路与铁道工程]