砂卵石地层矿山法隧道近距离穿越既有线关键技术研究  

Research on key technologies for tunnel mining with short distance beneath existing metro lines in gravel stratum

作　　者：戴志仁[1,2] 任建 王俊[1,2] 李小强[1,2] DAI Zhiren;REN Jian;WANG Jun;LI Xiaogiang(Shaanxi Railway and Underground Traffic Engineering Key Laboratory,Xi'an 710043,China;State Key Laboratory of Rail Transit Engineering Informatization,China Railway First Survey &.Design Institute Group Co.Ltd.,Xi'an 710043,China;Chengdu Metro Line Operation Co.,Ltd.,Chengdu 610041,China)

机构地区：[1]中铁第一勘察设计院集团有限公司陕西省铁道及地下交通工程重点实验室,西安710043 [2]中铁第一勘察设计院集团有限公司轨道交通工程信息化国家重点实验室,西安710043 [3]成都地铁运营有限公司,成都610041

出　　处：《北京交通大学学报》2019年第4期1-8,共8页JOURNAL OF BEIJING JIAOTONG UNIVERSITY

基　　金：陕西省重点科技创新团队计划(2016KCT-07)~~

摘　　要：针对富水砂卵石地层新建隧道超小净距离下穿已运营地铁盾构隧道工程,对既有线保护涉及的隧道穿越工法进行了全面比较,研究了矿山法隧道涉及的地层超前支护方式,并采用数值计算与理论分析相结合的手段从受力转换与拱顶应力释放控制角度对隧道衬砌结构选型进行了探讨,研究结果表明:矿山法隧道近距离下穿既有运营地铁隧道具有一定优势;矿山法隧道大管棚超前支护形成的钢筋砼扣拱,具有明显的隔断开挖扰动、减小地层应力释放的作用,发现钢管套打工艺可有效解决砂卵石地层钢管难以打入的难题;初期支护十二次衬砌十三次衬砌的结构型式可显著减小隧道永久结构施工期间的应力释放与围岩变形,最大程度减少结构受力体系转换过程中的应力释放与地层变形,确保满足既有线安全运营需求,研究结论可为类似工程提供借鉴与参考.With the topic of tunnel mining beneath the operating metro shield tunnel in gravel stratum,in order to preserve the existing lines,comprehensive comparison of related tunneling method is made,the ground advance support pattern linked with tunnel mining is studied.With the combination of numerical simulation and theoretical analysis,the lining structure type of tunnel is studied based on the stress conversion and the angle control of stress relief at the vault,According to the results,tunnel mining with short distance beneath existing metro lines bears certain advantages;besides,the large pipe shed produced by advance support of reinforced concrete can effectively isolate the ground disturbance during tunnel excavation and decrease stratum stress relief;as for advance ground grouting process,set-up method is adopted to overcome the drilling difficulties in gravel ground;lastly,to reduce the stress relief and ground deformation duringpermanent structural construction,the composite structure of initial support secondary-tertiary lining are put forward,which can minimize stress relief and ground deformation under the changing force structure,ensuring the safe operation of existing metro lines.This study can provide references for similar projects.

关 键 词：矿山法隧道 富水砂卵石 近距离穿越 大管棚 二衬+三衬结构 

分 类 号：U451[建筑科学—桥梁与隧道工程]