软土地区通缝拼装盾构隧道纵向变形特征  

Longitudinal Deformation Characteristics of Shield Tunnel with Straight Joint in Soft Soil

作　　者：李翔宇[1] 李明宇[1] 冯雷[1] 

机构地区：[1]同济大学地下建筑与工程系,上海200092

出　　处：《沈阳建筑大学学报（自然科学版）》2012年第3期411-416,共6页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家自然科学基金项目(50808137);教育部新世纪优秀人才支持计划项目(NCET-05-0386)

摘　　要：目的为进一步探求上海地区通缝拼装盾构隧道结构的纵向变形机理,得到各纵向变形特征时环缝张开量或环间错台的分布特征.方法根据上海地铁典型盾构隧道环缝接头处的详细构造,利用解析方法分别对隧道处于环间张角、错台和张角错台并存三种变形特征时的纵向变形机理进行了研究.结果环间仅出现张角时,衬砌结构的环缝张开量与环宽和外径成正比,与纵向弯曲变形曲率半径成反比;若隧道纵向变形为高斯曲线形式,反弯点i处,环间张角方向发生改变,最大环间张角出现在纵向变形曲线x=槡3i处的拱顶环缝位置.环间仅出现错台时,若隧道纵向变形为高斯曲线形式,环间错台量的峰值出现在反弯点i处,较大的环间错台量出现在隧道纵向变形曲线直线区段.相对只发生环间张角或错台,张角和错台的同时发展,将加剧衬砌结构的破坏程度,使密封垫更快失去防水作用.结论提出了隧道衬砌结构环间变形的各阶段环缝张开量的计算方法.研究成果可为运营地铁盾构隧道的结构安全评判提供理论参考.In order to study the longitudinal deformation mechanism of shield tunnel structure with straight joint in Shanghai, distribution characteristics of ring joint opening or dislocation, and calculation methods of ring joint opening in every stage during the ring joint deformation are analyzed in this paper. According to the typical detailed structure at the ring joint of local shield tunnels, the analytical method is adopted to re- search the mechanism of longitudinal deformation of tunnel under three different characteristics, which are dislocation, opening and coexistence of the both. When longitudinal deformation characteristics of tunnel present as opening only, the ring opening value is proportional to ring length and outer diameter respective- ly, and inversely proportional to curvature radius. When tunnel longitudinal deformation curve is expressed by Gaussian function in this case, the direction of ring joint opening changes at the inflection point x = √3i, and the opening angle reaches peak at ＇the point. When longitudinal deformation characteristics of tunnel present as dislocation only, and longitudinal deformation curve is expressed by Gaussian function, the dislo- cation value reaches peak at the inflection point i, and the larger dislocation deformation concentrates on thelinear part of the tunnel longitudinal deformation. It is shown that simultaneous development of opening and dislocation intensifies the degree of damage of lining structure, and makes the gasket lost waterproofing effect more quickly, compared with opening or dislocation only. All these conclusions above can provide theory references for safety assessment of operational subway structures.

关 键 词：盾构隧道 通缝拼装 纵向变形 环缝张开量 环间错台 

分 类 号：U451[建筑科学—桥梁与隧道工程]