大直径泥水盾构下穿地铁挡墙路基沉降控制  

Settlement Control on Retaining Wall Embankment Affected byUnderneath Traversing Large-diameter Slurry Shield Tunnels

作　　者：马文辉[1] 杨成永[1] 彭华[1] 白雁[1] 程霖[1] 高利宏[2] 刘志暘 MA Wenhui;YANG Chengyong;PENG Hua;BAI Yan;CHENG Lin;GAO Lihong;LIU Zhiyang(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;Beijing Subway Ltd,Beijing 100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]北京市地铁运营有限公司,北京100044

出　　处：《湖南大学学报（自然科学版）》2020年第3期44-53,共10页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51478032,51578053)。

摘　　要：为研究泥水盾构双洞先后下穿施工影响下既有挡墙式路基的沉降控制措施,依托京沈客专望京双洞盾构隧道施工下穿北京机场线路基工程,通过分析现场监测数据及盾构施工参数,在阐明了路基的沉降规律基础上,总结了控制沉降的盾构施工参数调控和注浆加固、沉降补偿的经验.研究结果表明:掘进各参数间、泥浆各参数间的关联密切;合理且较高的顶推力和泥水压力、较高比重和黏度的浆液可确保在地层扰动小的情况下盾构快速通过穿越段;理论注浆量2.5倍的同步注浆量和大于泥水仓压力0.15~0.2 MPa的注浆压力可确保盾尾建筑空隙充填密实;地表预注浆充分改良加固了地层、适度抬升了路基,注浆压力1.2 MPa的地表跟踪注浆及时有效地抑制、补偿了路基沉降,注浆压力1.2 MPa和速度100 L/min的隧洞内加强注浆减小了路基工后沉降.To investigate the settlement control measurement on the retaining wall embankment under the dual slurry shield tunnels underneath traversing construction,taking the retaining wall embankment in Beijing Capital Airport Express Line at Wangjing on Beijing-Shenyang passenger high-speed railway line as engineering back-ground,in-situ settlement monitoring data and shield construction parameters were analyzed.Settlement regulations of the embankment were narrated.Experiences on real-time adjustment of shield construction parameters,compre-hensive use of pre-grouting,supplementary grouting and secondary grouting were summarized.The measurement re-sults show that the relationship among tunneling parameters,as well as slurry parameters,is close.A relatively high thrust force,slurry pressure,slurry unit weight and slurry viscosity are the key parameters that ensure the shield to traverse quickly and safely with small disturbance to the embankment.Synchronous grouting at a pressure is 0.15~0.2 MPa greater than the slurry pressure and with a volume about 2.5 times the theoretical value can fully fill the shield tail void.Ground pre-grouting effectively improves the soil and moderately raises the embankment.Ground supple-mentary grouting at a pressure of 1.2 MPa can timely restrain and even compensate the settlement of the embankment.Secondary grouting in tunnels at a pressure of 1.2 MPa and a speed of 100 L/min reduces the post-construction settle-ment of the embankment.

关 键 词：盾构隧道施工 穿越施工 挡墙路基 沉降监测 施工参数 沉降控制 

分 类 号：U25[交通运输工程—道路与铁道工程]