三车道公路隧道出口段安全进洞施工技术  

Safe Construction Technology of Three-Lane Highway Tunnel at Portal Section

作　　者：谭常喜 TAN Changxi(rd Engineering Co.,Ltd.,China Railway 14th Bureau Group Corporation,Ji'nan 250300,China)

机构地区：[1]中铁十四局集团第三工程有限公司,山东济南272100

出　　处：《国防交通工程与技术》2023年第4期62-65,共4页Traffic Engineering and Technology for National Defence

摘　　要：勤丰隧道为双向六车道分离式结构型式。隧道右线出口浅埋段埋深从3.5 m到33.5 m,围岩为强风化花岗岩及泥岩。隧道断面开挖宽度达17.15 m,因隧道埋深浅,进洞施工引起的隧道变形易传递至地表,施工风险较高。通过导向套拱保证大管棚施工精度以实现较好的超前支护效果,采用CRD法分部开挖进洞,使支护及临时支护及时形成封闭结构,可以有效控制地层变形。施工监测结果表明:所采用施工方案很好地控制了地层变形,保证了勤丰隧道右洞出口段进洞施工安全。Qinfeng Tunnel is designed as a two-way six-lane separated structure type.The depth of the shallow buried section at the right exit of the tunnel ranges from 3.5 m to 33.5 m.The surrounding rock is mainly strongly weathered granite and mudstone.The excavation width of the tunnel section reaches 17.15 m.Due to the shallow burial depth of the tunnel,the deformation caused by the tunnel excavation is easy to transfer to the surface.The construction risk is high.The construction accuracy of the large pipe shed is ensured by guiding the sheath arch to achieve a better advance support effect.The CRD method was adopted at the portal section of the tunnel,so that the support and temporary support could come into a closed structure in time to control the ground deformation effectively.The construction results shows that the adoptted construction scheme could control the ground movement well and ensure the construction safety at the right portal section of Qinfeng Tunnel.

关 键 词：三车道公路隧道 进洞施工 导向套拱 CRD法 变形监测 

分 类 号：U455.41[建筑科学—桥梁与隧道工程]