城际铁路隧道深大圆形竖井开挖阶段变形监测分析  

Deformation Monitoring and Analysis during the Excavation of Deep Circular Shafts in Intercity Railway Tunnels

作　　者：宋越鹏 范晓锋 梁禹 彭红国 张晗炜 SONG Yuepeng;FAN Xiaofeng;LIANG Yu;PENG Hongguo;ZHANG Hanwei(Shenzhen Metro Group Co.,Ltd.,Shenzhen 518000;School of Aeronautics and Astronautics,Sun Yat-Sen University,Shenzhen 518107;School of Civil Engineering,Sun Yat-sen University,Zhuhai 519082;Southern Marine Science Engineering Guangdon Laboratory,Zhuhai 519082;The Third Engineering Co.Ltd of China Railway Seventh Group,Xi′an 710032)

机构地区：[1]深圳地铁集团有限公司,深圳518000 [2]中山大学·深圳航空航天学院,深圳518107 [3]中山大学土木工程学院,珠海519082 [4]南方海洋科学与工程广东省实验室,珠海519082 [5]中铁七局集团第三工程有限公司,西安710000

出　　处：《现代隧道技术》2024年第5期219-226,共8页Modern Tunnelling Technology

基　　金：国家自然科学基金(52378427);广东省基础与应用基础研究基金(2023A1515030258、2024A1515012623);深圳市科技计划项目可持续发展专项(KCXFZ20201221173207020)。

摘　　要：盾构始发与接收工作井的支护体系选取与设计是深埋隧道建设过程中的关键问题。圆形围护结构以其可充分发挥土拱效应,无需内撑等特点,较一般多边形结构体系具有更优的受力性能与经济性。为降低土岩复合地层中嵌岩部分施工难度及提高施工效率,以深大城际铁路隧道坪聚盾构工作井应用上部圆形吊脚地连墙+环框梁、下部岩层喷锚支护方式的结构形式为工程依托,对深埋圆形基坑开挖过程中坑外地下水位变化、地表及围护结构变形监测数据开展研究分析。研究结果表明:地面超载、坑外地下水位不均匀分布会引起墙体及地表产生差异变形;墙体最大水平变形基本位于0~0.05%H(H为基坑开挖深度)以内;地表沉降变形大部分位于0~0.08%H以内;墙顶竖向沉降值大部分位于0~0.25%H;相比一般不规则多边形基坑支护,圆筒形支护体系显示出较好的稳定性与抗变形能力;在土岩复合地层中,上部采用地连墙+环框梁,下部岩层采用喷锚支护的结构形式可保证基坑稳定性,安全性较好。The selection and design of the support system for the launching and receiving shafts of shield tunnelling are critical issues in the construction of deep-buried tunnels.Circular enclosure structures can fully utilize the arch effect of soil and do not require internal supports,providing better mechanical performance and cost-effectiveness compared to general polygonal structures.To reduce the construction difficulty and improve efficiency in the rockembedded section of composite strata,the Shenzhen International Airport-Dayawan intercity railway tunnel′s Pingju shield working shaft adopts an upper circular diaphragm wall combined with a ring beam and a lower layer of rock support using shotcrete and anchor bolts.This study analyzes changes in external groundwater,ground surface,and enclosure structure deformation during the excavation of the deep circular foundation pit.The results indicate that:surface overload and uneven external groundwater levels cause differential deformation of the wall and ground surface;the maximum horizontal deformation of the wall is generally within 0 to 0.05%H(H is the excavation depth);most ground surface settlement deformation is within 0 to 0.08%H;the vertical settlement at the top of the wall mostly ranges from 0 to 0.25%H;compared to general irregular polygonal foundation pits,the cylindrical support system shows better stability and deformation performance;the combined use of diaphragm walls with ring beams in the upper section and shotcrete and anchor bolts in the lower rock layer ensures the stability and safety of the foundation pit in composite strata.

关 键 词：铁路隧道 圆形基坑 现场实测 深基坑 地下水影响 不均匀变形 变形性状 

分 类 号：U459.1[建筑科学—桥梁与隧道工程]