光面爆破技术在向莆铁路青云山特长隧道工程中的应用

光面爆破设计是隧道工程建设确保质量安全的核心技术要素。青云山特长隧道是向莆铁路重点控制性工程,采用钻爆法施工;隧道围岩以Ⅱ～Ⅲ级为主,采用全断面法开挖;进出口与浅埋段等为IV、V级围岩,采用台阶法施工;围岩较差段采用弧形开挖预留核心土法施工。不同级别围岩采用了针对性的爆破设计,取得了满意的爆破效果。实践证明,适当加密周边眼、合理确定光面爆破层厚度、采用小直径药卷不耦合装药结构、保证爆破眼同时起爆是光面爆破成功应用的关键。

Application of Smooth Blasting to the Qingyunshan Tunnel on the Xiangtang-Putian Railway

Smooth blasting is a key technical element in ensuring the quality and safety of tunnel construction.The Qingyunshan Extra-long Tunnel on the Xiangtang-Putian Railway,which is one of its key projects,was built using the drilling-and-blasting method.For the surrounding rock of classes II-III,a full-face excavation was carried out.The bench method was used for the entrance,exit and the shallow-buried section with surrounding rock of classes IV and V.For poor quality rock masses,arc excavation with a reserved ...