四线隧道密贴下穿既有地铁车站注浆加固圆砾石地层效果研究  

Research on the Effect of Grouting Reinforcement of Gravel Stratum in the Four-line Tunnel Closely Undercrossing the Existing Metro Station

作　　者：寇鼎涛[1,2] 高太平 闫建龙 申健昊 李刚 李昊炎 沈宇鹏 KOU Dingtao;GAO Taiping;YAN Jianlong;SHEN Jianhao;LI Gang;LI Haoyan;SHEN Yupeng(Beijing MTR Construction Administration Corporation,Beijing 100068,China;Beijing Key Laboratory of Fully Automatic Operation and Safety Monitoring for Urban Rail Transit,Beijing100068,China;The Third Construction Co.,Ltd.of CETC Group,Tianjin 300011,China;School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京市轨道交通建设管理有限公司,北京100068 [2]城市轨道交通全自动运行系统与安全监控北京市重点实验室,北京100068 [3]中铁四局集团有限公司第三建设有限公司,天津300011 [4]北京交通大学土木建筑工程学院,北京100044

出　　处：《铁道标准设计》2020年第12期94-100,共7页Railway Standard Design

基　　金：国家重点研发计划项目(2017YFC0805305);中国铁路总公司科技研究开发计划项目(P2018G04)。

摘　　要：为研究注浆加固在浅埋暗挖隧道下穿既有车站工程中对卵石圆砾地层的加固效果,以北京地铁19号线四线隧道密贴下穿既有4号线新宫站工程为背景,以数值模拟和现场监测相结合的方法,分析既有结构在不同注浆加固范围及注浆强度工况下的沉降变形特征。研究结果表明:(1)土体开挖过程中既有结构沉降逐渐回升,二衬施作过程中既有结构沉降迅速增大。(2)施工过程中对地层进行深孔注浆预加固可有效控制既有结构的沉降变形;(3)其他条件一定时,既有结构沉降随注浆加固范围的增大而减小并最终趋于稳定,综合考虑施工安全及施工成本,本项目注浆加固范围取隧道轮廓线外2m为宜;(4)其他条件一定时,既有结构沉降随注浆强度的增大而减小并最终趋于稳定,在控制既有结构沉降方面,其他条件一定时,增大注浆加固范围比增大注浆强度更有效。In order to study the reinforcement effect of grouting reinforcement technology on the gravel stratum in the project of shallow buried tunnels undercrossing the existing station,the settlement and deformation characteristics of the existing structure under different grouting reinforcement range and grouting strength are analyzed by combing numerical simulation with on-site monitoring based on the project of four-line tunnel of Beijing Metro Line 19 closely undercrossing the existing Xingong Station of line 4.The research results show that:(1)In the process of soil excavation,the settlement of existing structure decreases gradually,and the settlement of existing structure increases rapidly in the process of secondary lining construction;(2)The settlement and deformation of existing structure can be effectively controlled by taking the grouting reinforcement technology for stratum pre-reinforcement in the construction process;(3)When other conditions are certain,the settlement of existing structure decreases with the increase of grouting reinforcement range and finally tends to be stable.Considering the construction safety and construction cost,the grouting reinforcement range of the project is suitable for 2 m outside the tunnel contour line;⑷When other conditions are certain,the settlement of existing structure decreases with the increase of grouting strength and finally tends to be stable.When other conditions are certain,it is more effective to increase the grouting reinforcement range than to increase the grouting strength in controlling the settlement of existing structure.

关 键 词：密贴下穿工程 注浆加固 既有地铁车站 数值模拟 沉降控制 优化分析 

分 类 号：U455[建筑科学—桥梁与隧道工程]