繁华城区极硬地层连拱隧道施工技术探讨

Discussion on Construction Technology of Multi-arch Tunnel in Extremely Hard Stratum in Busy Urban Area

摘要:

针对硬岩地质条件，公路隧道通常采用钻爆法进行开挖。当新建隧道处于复杂环境，尤其是穿越繁华城区时，隧道周边往往有许多建（构）筑物及既有隧道等，施工中的爆破振动会不可避免地对周边建（构）筑物的结构安全以及居民区造成不利影响。依托深圳市望海路微波山隧道工程项目，探讨了不同开挖方案下的施工效益。结果表明：采用钻爆法施工时，爆破引起的既有地铁隧道振动速率大于1.2 cm/s；采用其他非爆破方法施工时，开挖功效低于0.1 m/d，且修边工作量大；采用悬臂式掘进机技术施工时，其单日开挖功效可达1.0~1.5 m/d，且施工带来的振动和噪声较小，隧道成型效果更好，开挖效率更高。

Abstract:

In view of hard rock geological conditions, the highway tunnels are usually excavated by drilling and blasting method. When a new tunnel is in a complex environment, especially through a busy urban area, there are often many buildings （structures) and existing tunnels around the tunnel. The blasting vibration during construction will inevitably cause the adverse effects on the structural safety of the surrounding buildings （structures) and residential areas. Supported by the Shenzhen Wanghai Road Weibo Mountain Tunnel Project, the construction benefits with the different excavation schemes are discussed. The result shows that when the drilling and blasting method is used, the vibration rate of the existing subway tunnel caused by blasting is greater than 12 mm/s. When the other non-blasting construction methods are used, the excavation efficiency is less than 0.1 m/d, and the trimming workload is large. When the cantilever tunneling machine technology is used for construction, the tunneling efficiency per day can be 1.0~1.5 m/d, and the vibration and noise caused by the construction are small. The tunnel forming effect is better, and the excavation efficiency is higher.