浅埋偏压黄土隧洞进洞方案与施工技术

山西省大水网的建设中隧洞工程较多,超前小导管和钢拱架联合支护作为隧洞洞口及通过软弱破碎带之主要辅助工法,由于其施工速度快、安全性高、工期短,目前已广泛应用于隧洞工程。山西省中部引黄工程交汾灵支线2号隧洞出口为浅埋偏压黄土洞段,文中就此洞口的进洞方案与施工技术做了介绍,工程实践表明,其有效地减小了地表下沉和围岩变形,达到了确保不良地质段安全施工的目标。

The Construction Scheme and Technique for the Entrance Excavation of Shallow-buried Loess Tunnel Bearing Asymmetric Earth Load

There are many tunnel projects in construction of Shanhai Water Network.The supporting structure combining the advanced small pipe with steel arch,as the main auxiliary construction method adopted in the tunnel entrance and in the weak fracture zone,has widely been used in tunnel construction because of its fast speed,high safety and short construction period.The NO.2 outlet tunnel in Jiao-Fen-Ling Branch Line of Yellow River Diversion Project in Central Shanxi Province is a shallowly-buried loess tunnel bearing asymmetric earth load.The paper introduces the construction scheme and technique using this method to excavate this tunnel.The project practice indicates that this method can effectively reduce the surface subsidence and deformation of surrounding rock,and the target of safety construction in bad geological condition can be ensured.