密贴下穿既有地铁车站的新建通道拆撑影响分析  

Analysis on the Influence of Removing the Temporary Lining on the Underpass Tunnel Passing Right Under Metro Station

作　　者：曹攀 章慧健[1,2] 杨宇杰 张帅[1,2] 郭宏博 CAO Pan;ZHANG Huijian;YANG Yujie;ZHANG Shuai;GUO Hongbo(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;Southwest Jiaotong University School of Civil Engineering,Chengdu 610031,China;Guangzhou Metro Design&Research Institute Co.,Ltd.,Guangzhou 510010,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]西南交通大学土木工程学院,成都610031 [3]广州地铁设计研究院股份有限公司,广州510010

出　　处：《铁道标准设计》2024年第2期158-166,共9页Railway Standard Design

基　　金：国家重点研发计划项目(2017YFC0806006);国家自然科学基金项目(52178395)。

摘　　要：依托成都地铁8号线倪家桥站零距离密贴下穿既有地铁1号线倪家桥车站工程,采用数值模拟方法对比分析“先施作二衬再拆撑”和“先拆撑再施作二衬”对既有和新建结构的力学差异,并基于“先拆撑再施作二衬”工况进一步分析拆撑方案,最后通过实测现场实施的“先施作二衬再拆撑”工序下的既有车站底板沉降数据验证相关结论。研究结果表明:“先施作二衬再拆撑”既有车站弯矩及沉降、新建通道初支弯矩及二衬沉降变化不明显;“先拆撑再施作二衬”对于既有车站及新建通道影响则较为显著,一次性全部拆撑后既有及新建结构弯矩沿断面分布形态变化明显,在结构沉降方面,拆撑后既有车站及新建通道初支最大沉降突变量分别达4.86,7.30 mm;“先拆撑再施作二衬”工况下,采用顺序拆撑与跳仓拆撑,最不利部位出现在下穿通道纵向中部,跳仓拆撑引起新建通道初支沉降量大于顺序拆撑,但其施工效率更高,具体拆撑方式应根据施工安全控制标准及经济性要求合理选择。Based on the newly-built underpass tunnel of Nijiaqiao station in Chengdu Metro Line 8,which passes right under metro station of Line 1,and numerical simulation method is performed to compare and analyze the influence on the newly-built and existing structure between removing the temporary lining first and second lining first.Based on the working condition of “removal of temporary lining before the secondary liner”,the plan of removing the support is further analyzed.Moreover,some results are verified by the on-site monitoring data.The main results show that:in the case of second lining first,the bending moment and settlement of the existing station and the preliminary lining bending moment and the secondary lining settlement of the new channel caused by the removal of the temporary lining are not obvious;for the case of temporary lining first,after all the temporary linings are removed at one time,the bending moments of existing and new structures change greatly along the section.In terms of structural settlement,the maximum sudden settlement of the preliminary lining of existing stations and new channels after the removal of temporary lining reaches 4.86 mm and 7.30 mm respectively.Basing on removing the temporary lining first,the most disadvantageous part occurs in the longitudinal middle of the underpass when the temporary lining is removed in sequence and removed by jumping.The settlement of the preliminary lining of the newly-built channel caused by the jumping is larger than that of the sequential dismantling,but its construction efficiency is higher.The specific method should be reasonably selected according to the construction safety standard and the economic requirements.

关 键 词：地铁车站 密贴下穿 临时支撑 内力分析 现场监测 拆撑方案 

分 类 号：U231[交通运输工程—道路与铁道工程]