新建地铁车站上穿既有地铁结构的变形控制  

Control of the Existing Subway Structure Deformation Induced by the Adjacent Overcrossing Newly-Built Subway Station

作　　者：许有俊[1] 聂鑫路 魏云杰[3] 银英姿[1] 鲍先凯[1] 

机构地区：[1]内蒙古科技大学建筑与土木工程学院,包头014010 [2]重庆市轨道交通建设办公室,重庆400014 [3]中国地质环境监测院,北京100081

出　　处：《地下空间与工程学报》2016年第1期153-161,共9页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(41172254);内蒙古自治区高等学校科学技术研究项目(NJZY14167)

摘　　要：以北京地铁4号线西单站上穿既有1号线区间隧道工程为背景,对新建地铁车站近距离上穿既有线过程中既有地铁结构的分步变形控制标准及技术进行研究,主要得到以下结论:(1)施工前对既有地铁结构进行检测与评估,既有1号线区间结构已超出安全临界状态,需对既有结构二衬进行加固。(2)采用FLAC3D软件建立三维地层-结构模型,基于变位分配原理,将上浮变形控制值按关键施工步序分解,按照控制值的70%、80%作为预警值、报警值,制定分步变形控制标准。(3)施工过程中,按照浅埋暗挖法"十八字"方针,采取既有结构周围土体袖阀管深孔注浆加固、中空预应力抗浮锚杆等技术抑制既有结构的上浮变形等措施。(4)既有结构的最大上浮值为2.1 mm,左、右线第2层、第3层导洞的开挖是引起既有线上浮的主要原因,纵向变形模式基本符合正态分布曲线;轨道结构累计最大上浮值为2.9 mm。Based on the project of Xidan station of the Metro Line 4 over crossing the Metro Line 1 tunnel in Beijing,the step deformation control standard and technical measures are studied in the construction process of the newly-built subway station over crossing the existing subway structure. The study results are as follows： 1. The existing structure is checked and evaluated before the construction,and the structure of Metro Line 1 is beyond the safety critical condition,and the liner should be consolidated. 2. A 3D model considering the interactions between stratum and structure is established by using the software FLAC3 D,and the deformation control value is divided according to the key construction sequence in terms of principles of displacement distribution,and 70%,80% of the control value is respectively set as warning and alarm values,then the step deformation control standard is laid down. 3. According to the principles of Shallow Tunneling Methods,such technical measures as grouting consolidation of surrounding soil of the existing structure and anti-floating cable are applied to alleviate the floating deformation of the existing structure during the construction. 4.The results show that the maximum floating displacement of the existing structure is about2.1 mm,and the main deformation is induced by the excavation of the 2nd and 3rd drift,and the longitudinal deformation of the existing tunnel basically conform with the normal distribution curve,and the cumulative maximum floating displacement of the existing rail structure is about 2.9 mm.

关 键 词：地铁车站 上穿 既有地铁结构 变形控制 

分 类 号：TU43[建筑科学—岩土工程]