大断面通道近距离上穿盾构隧道引起的变形分析  

DEFORMATION ANALYSIS FOR SHIELD TUNNEL UPPER CROSSING BY CLOSE RANGE LARGE SECTION PASSAGEWAY

作　　者：贺美德[1,2] 刘军[3] 乐贵平[4] 张顶立[1] 王梦恕[1] 

机构地区：[1]北京交通大学隧道及地下工程教育部工程研究中心,北京100044 [2]北京市市政工程研究院,北京100037 [3]北京建筑大学土木与交通工程学院,北京100044 [4]北京市轨道交通建设管理有限公司,北京100037

出　　处：《岩石力学与工程学报》2014年第A02期3682-3691,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：北京市自然科学基金项目;北京市科技计划重点项目(KZ201310016016);北京市属高等学校创新团队建设与教师职业发展计划项目(IDHT20130512)

摘　　要：以北京地区大断面地下人行通道工程近距离上穿最小净距仅1.97 m的地铁10号线盾构隧道为背景,采用浅埋暗挖CRD法上穿盾构隧道施工,根据工程特点,分别对东线和西线隧道结构竖向位移、隧道结构水平收敛位移及道床结构竖向位移3种变形进行监测、分析。现场实测结果表明:(1)大断面通道上穿施工引起的既有地铁隧道结构变形以上浮为主,隧道结构竖向位移为-0.10~4.10 mm、水平收敛位移为-0.03^-1.80 mm、道床竖向位移为-0.30~2.90 mm,隧道结构与道床结构变形协调。(2)隧道结构竖向位移、水平收敛位移及道床结构竖向位移的变化规律一致,均经历了快速上升区、急速回落区、波动下降区及后期波动稳定区4个阶段。在通道掌子面开挖通过盾构隧道后,隧道结构的上浮变形速率明显加大,呈现陡升趋势;通过通道底板向下注浆后,隧道的整体上浮受到明显控制;向下注浆结束后,隧道的上浮变形速率已趋于平缓;通道二衬结构完成后,由于上部荷载的增加使得隧道整体变形呈波动下沉,并最终趋于稳定。可见,通道内注浆对于控制盾构隧道结构上浮作用明显,为今后类似工程提供借鉴。During the upper crossing construction process in the project of a certain large section pedestrian passageway upper crossing the running shield tunnel of Beijing subway line No.10,the vertical displacements of shield tunnel structure,the horizontal convergence displacements of shield tunnel structure and the vertical displacements of track bad structure were monitored and analyzed. In this section,the minimum distance was 1.97 m and the CRD method of shallow tunneling was applied. The site monitoring results show that：（1） The deformation of existing subway tunnel structure due to the large section passageway construction is mainly resulted from up floating. The vertical displacement of shield tunnel structure varies from-0.10 to 4.10 mm;the horizontal convergence of shield tunnel structure ranges from- 0.03 to- 1.80 mm; while the vertical displacement of track bad structure is from-0.30 to 2.90 mm. And the deformations of tunnel structure and track bed structure are coordinating.（2） The variations of three monitoring indices are consistent. They all experience four stages,the upward rapidly area,the down abruptly area,the fluctuating decreased area and the later fluctuating stability area. After completing the tunnel face of passageway,the up floating deformation rate of tunnel structure is significantly increased. When grouting from the floor of passageway,however,it is obvious that grouting controls the up floating deformation of tunnel. When the grouting is completed,the up-floating deformation rate of tunnel structure becomes flat. After the secondary lining of passageway is completed,the tunnel overall is sinking with fluctuation because of the load above shield tunnel increase,and finally reaches stable. The analysis result of this project shows that grouting from floor of passageway can significantly control up floating,which can be applied in the similar projects.

关 键 词：隧道工程 盾构隧道 大断面 上穿施工 竖向位移 水平收敛位移 现场监测 

分 类 号：U45[建筑科学—桥梁与隧道工程]