砂卵石地层盾构隧道下穿铁路咽喉区地表沉降控制研究  

Study on the Control Measures against Ground Settlement Induced by Shield Tunnel Construction underneath Railway Throat in Sandy Cobble Stratum

作　　者：仇文革[1] 万世付 高刚刚 赵海霖 戚幸鑫 QIU Wenge;WAN Shifu;GAO Ganggang;ZHAO Hailin;QI Xingxin(Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu 610031)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031

出　　处：《现代隧道技术》2021年第5期37-45,共9页Modern Tunnelling Technology

基　　金：国家重点研发计划(2017YFC0806000)。

摘　　要：砂卵石地层岩体粘聚力小、自稳能力差,施工时极易发生坍塌,地表的沉降控制难度较大。为研究砂卵石地层中盾构下穿敏感区域时地表的沉降规律及控制措施,文章以成都地铁5号线下穿宝成铁路咽喉区为工程背景,采用工法比较、数值模拟、现场监测反馈等方法,提出了地表沉降的控制措施,阐明了地表沉降规律,验证了沉降控制措施的有效性。研究结果表明:在砂卵石地层中进行盾构施工时,使用双层大管棚结合地层跟踪注浆的工法对地层进行加固,实现对地表的沉降控制,是合理且有效的;计算表明,地层加固后地表的沉降相较于不进行加固时减少了61.16%;使用全自动监测系统对地表沉降进行实时反馈与预警,监测数据表明,施工过程中地表最大沉降为1.29 mm,最大隆起为0.72 mm,验证了地层加固措施的有效性,确保了盾构掘进和运营铁路的安全。Sandy cobble stratum has little cohesion and poor self-stability capacity,and is very prone to collapse during tunnel construction,making it difficult to control the ground surface settlement.In order to study the ground surface settlement pattern and relevant control measures when a shield is driving under sensitive areas in sandy cobble stratum,this paper uses the Chengdu Metro Line 5,which passes under the throat area of Baocheng Railway,as the engineering context for the study.Through comparison of construction methods,numerical simulation and feedback from site monitoring,this paper proposes the control measures for and elucidates the pattern of the ground settlement,and verifies the effectiveness of the settlement control measures.The study results show that it is reasonable and effective to use the reinforcement measures such as the double-layered large pipe roof in combination with the ground tracing grouting method to control the ground settlement during the shield construction in sandy cobble stratum;calculations show that the ground surface settlement is reduced by 61.16%after consolidation of the strata compared to that without consolidation;using fully automatic monitoring system for real-time feedback and early warning of ground settlement,the monitoring data show that the maximum ground settlement during construction is 1.29 mm and the maximum heaving is 0.72 mm,which verifies the effectiveness of the ground reinforcement measures and ensures the safety of shield tunnelling and railway operation.

关 键 词：盾构隧道 砂卵石地层 地层加固 大管棚 跟踪注浆 数值模拟 地表沉降 现场监测 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]