摘要
为探究不同近接度下新建隧道下穿施工对既有隧道结构造成的影响,以成都地铁30号线下穿既有成自高铁锦绣隧道为依托工程,采用理论研究的方法提出近接影响度表达式,并通过结构位移判别准则确定分区控制标准。采用数值模拟、回归分析的方法,对下穿施工近接影响范围进行量化分区,并对不同影响分区提出针对性控制措施。结果表明,既有隧道管片最大沉降值与新建隧道和既有隧道之间的净距、新建隧道左线和右线之间的间距都呈负相关;针对在强影响区中施工提出“门式”保护结构,可将既有隧道管片最大沉降值折减77.10%,针对在弱影响区中施工提出新建隧道管片壁后注浆加固,可将既有隧道管片最大沉降值折减56.86%。监测结果表明,采取合理的施工控制措施,可有效控制既有隧道结构的位移,将既有隧道管片最大沉降值控制在预警值6 mm内。
In order to explore the impact of new undercrossing tunnel on the existing tunnel structure under different adjacent degrees,based on the Chengdu Subway Line 30 undercrossing the existing Jinxiu Tunnel on ChengduZigong High Speed Railway,the expression for adjacent impact degree is proposed by the theoretical research method,and the impact zoning control standard is determined by the structural displacement discrimination criteria.Numerical simulation and regression analysis methods are used to quantify and zone the adjacent impact range of the undercrossing construction,and targeted control measures are proposed for different impact zoning.The results show that the maximum settlement of existing tunnel segments is negatively correlated with the net distance between the newly-built tunnel and the existing tunnel,as well as the separation distance between left and right lines of the newly-built tunnel.A"gate"type protection structure is proposed for construction in the strong impact zone,which can reduce the maximum settlement of existing tunnel segments by 77.10%.For construction in weak impact zones,grouting reinforcement is proposed behind new tunnel segment walls,which can reduce the maximum settlement of existing tunnel segments by 56.86%.The monitoring results indicate that reasonable construction control measures can effectively control the displacement of the existing tunnel structure,and control the maximum settlement of the existing tunnel segment within the warning value of 6 mm.
作者
范文昊
谢盛昊
周飞聪
王志杰
张凯
骆云建
FAN Wenhao;XIE Shenghao;ZHOU Feicong;WANG Zhijie;ZHANG Kai;LUO Yunjian(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031;The First Engineering Company of CCCC Forth Harbor Engineering Co.,Ltd.,Guangzhou 510310)
出处
《现代隧道技术》
CSCD
北大核心
2023年第4期43-57,共15页
Modern Tunnelling Technology
基金
国家自然科学基金(52278417).
关键词
双线盾构隧道
下穿施工
管片沉降
近接影响分区
控制措施
施工监测
Double-line shield tunnel
Undercrossing construction
Segment settlement
Adjacent impact zoning
Control measures
Construction monitoring