大断面偏压隧道超浅埋洞口施工关键技术  

Key Construction Technologies for Super-Shallow Burial Tunnel Portals in Large Cross-section Skewed Tunnels

作　　者：赵金洪 陈绍清 刘恒瑞 ZHAO Jinhong;CHEN Shaoqing;LIU Hengrui

机构地区：[1]重庆高新技术产业开发区城市建设事务中心,重庆401329 [2]重庆科技大学安全工程学院,重庆401331

出　　处：《重庆建筑》2024年第6期44-47,共4页Chongqing Architecture

摘　　要：隧道暗挖施工的安全影响因素较多,特别是在隧道洞口地质环境条件较差时,生产安全事故控制难度更大。该文以文峰山1#隧道急倾斜地层四车道大断面洞口超浅埋段为例,通过采取地面注浆加固,施作洞门套拱和打超长管棚作为进洞条件;洞身开挖采用双侧壁导坑七步工法,首先完成超前小导管施工,后采用大型配套机械挖掘,减少扰动,控制台阶间作业面距离及左右导坑先后行的长度,以确保大倾角超浅埋段掌子面岩石的稳定性,实现小台阶快速成环,有效解决隧道进洞难的问题,达到早进洞的目标,对该隧道安全顺利完工提供了有力保障,对类似隧道项目的施工有重要的借鉴作用。Factors affecting the safety of the concealed excavation of tunnels are numerous,particularly challenging under adverse geological conditions at tunnel portals.This paper takes the supershallow buried section of the four-lane large cross-section tunnel portal with steeply inclined strata at Wenfengshan Tunnel#1 as a case study.Ground grouting reinforcement,construction of portal arch sleeves,and installation of ultra-long pipe sheds were employed as entry conditions.The seven-step dual-side wall heading method was used for tunnel excavation,accomplishing the construction of advanced small pipes,followed by large-scale mechanical excavation to minimize disturbances and control the workface distance between steps and the sequential length between the former and latter headings on the left and right,so as to ensure the stability of the rock face in the steeply inclined super-shallow burial section.This approach facilitated rapid small step ring construction,effectively resolving challenges in tunnel entry,achieving early entry goals,and providing robust security for the successful completion of the tunnel.These methods offer valuable insights for similar tunnel construction projects.

关 键 词：大断面隧道 偏压 超浅埋 施工技术 

分 类 号：U455[建筑科学—桥梁与隧道工程]