新奥法在大洞径洞室开挖施工中的应用

Application of New Austrian Tunneling Method in excavation of large-diameter tunnels

溪洛渡水电站右岸泄洪洞洞室开挖断面大,地质条件复杂,施工时如不重视开挖和支护的相互关系,就会造成塌方、冒顶等安全事故,带来一系列经济损失。主要介绍施工中根据新奥法施工原理编制的施工方案和组织施工,从开挖分层和支护形式上充分考虑施工期围岩安全稳定,规范施工程序,使支护作业面最大限度地紧跟开挖作业面施工,将动态的、随机的、不断变化和调整的开挖及支护工序变换过程,转化为相对固定的工作程序,以起到良好的效果。

As for the large cross-section tunnel excavation and complicated geological conditions,in the construction of discharge tunnel in the right bank of Xiluodu Hydropower Station,great importance shall be attached to the relationships between excavation and support,otherwise,collapse and roof fall may happen.We mainly present the construction schemes prepared based on the construction principles of New Austrian Tunneling Method（NATM）,taking full consideration of the safety and stability of surrounding rock in construction period from stratified excavation and support form,standardizing the construction procedures,making the supporting construction following the excavation to the greatest extend.As a result,the dynamic,random and changeable transformation process of excavation and support is transferred into relatively fixed construction procedures.