北京地铁7号线大郊亭站附属结构暗挖施工技术

Tunnelling Construction Technology for the Accessory Structure of Dajiaoting Station on Beijing Subway Line 7

北京地铁7号线大郊亭站附属结构中3、4号出入口通道因下穿广渠路,采用暗挖法施工。其施工受到多种因素的影响,施工技术难度大,安全风险高。结合施工现场实际,介绍了出入口通道暗挖中的超前小导管注浆、大管棚超前支护、上台阶环形开挖、CRD(交叉中隔壁法)及CD(中隔壁法)工法等施工技术。该工程总结了保证其施工质量和安全的控制措施,同时对富水软弱地层,以及平顶、直墙、断面结构变化多及围岩级别低等条件下的暗挖通道施工难点给出了解决方案,为今后类似环境条件下地铁通道施工提供参考。

In the accessory structure of Dajiaoting Station on Beijing metro Line 7, the No. 3 and No. 4 entrances are built by tunneling method, because their channels passing under the Guangqu Road,so the construction is affected by many factors, at the same time faces many technical diffi- culties and high security risks. In this paper, the actual con- struction methods are described in detail, including the ad- vanced small pipe grouting, bassoon shed advance support, the ring excavationon steps, CRD and CD construction methods in entrance channel tunneling, etc. To ensure the quality and safety of this project, the construction mea- suremts are summarised, solutions are found in adopting control measures, especially in conditions of the water-rich soft ground, the flat and straight walls, the changes in multi-sectional structure, etc., providing a reference for the construction of subway tunnel under the similar envi- ronmental conditions.