摘要
文章以万州北山隧道为工程背景,针对其下穿三峡库区枇杷坪古滑坡体、建筑群、浅埋大断面等特征,对双侧壁导坑法进行优化,通过FLAC 3D三维数值模拟对比分析双侧壁导坑法优化前后的围岩塑性区分布、应力场特征和沉降变形,并结合监测数据对优化后工法应用效果进行验证。结果表明:调整双侧壁导坑法各步断面尺寸和临时支撑拆除顺序,可明显降低施工阶段沉降变化速率,围岩变形和地表沉降可降低约1/3;拱部围岩压应力减小30%,对施工安全更有利;还可减少临时支撑干扰,降低施工难度,更利于机械化作业,提高施工效率,缩短导坑和全周初期支护封闭成环时间。
Based on the engineering background of Wanzhou Beishan Tunnel,the double-side drift method was optimized according to the characteristics of Pipaping ancient landslide mass,building complex and shallow-buried large section tunnel in the Three Gorges Reservoir Area in this paper.Then,the distribution of surrounding rock plastic zone,stress field characteristics and settlement deformation before and after the optimization of double-side drift method were compared and analyzed by FLAC 3 D three-dimensional numerical simulation.Finally,the application effect of the optimized construction method was verified in combination with the monitored data.The results indicate that the adjustment of sectional sizes in each step and removal sequence of temporary supports in the double-side drift method could significantly reduce the settlement change rate in the construction phase,so that the surrounding rock deformation and ground settlement could be reduced by about 1/3;the compressive stress of surrounding rock in vault could be reduced by 30%,which is more beneficial to construction safety;it could also reduce the interference of temporary support,decrease construction difficulty,be more conducive to mechanized operation,improve the construction efficiency and shorten the cloursing time of initial support of the pilot tunnel and main tunnel.
作者
李欣
郑帅恒
顾刚
LI Xin;ZHENG Shuaiheng;GU Gang(CCCC Fourth Navigation Engineering Bureau Co.,Ltd.,Guangzhou 510230;No.1 Engineering Co.,Ltd.of CCCC Fourth Navigation Engineering Bureau Co.,Ltd.,Guangzhou 510230;CCCC Fourth Harbor Engineering Researeh Institute Co.,Ltd.,Guangzhou 510230)
出处
《现代隧道技术》
CSCD
北大核心
2021年第S01期224-231,共8页
Modern Tunnelling Technology
基金
中交第四航务工程局有限公司科技课题(2020-A-02-I-01)
关键词
大断面
浅埋
下穿建筑群
双侧壁导坑法
Large section
Shallow buried depth
Passing under building complex
Double-side drift method
