复合地层盾构掘进施工中,基岩及孤石的存在对盾构施工有着较大的制约因素,未破碎的孤石与地层挤压不仅会造成地面塌陷和盾构机偏离掘进轨迹,还可能致使盾构机刀盘严重磨损。本文以福州地区某盾构区间基岩及孤石处理为例,从区间的地质条件、基岩凸起及孤石的危害、基岩及孤石形成的主要原因、爆破参数设计及主要工艺参数、爆破效果五个方面分析了基岩及孤石爆破处理方式。提出了合理的爆破方案、最佳炮孔距等参数,有效的解决了复合地层中高强度基岩及孤石对盾构掘进施工的影响。

In the construction of shield tunneling in composite strata, the presence of bedrock and orphan rock has significant constraints on shield tunneling. The compression of unbroken orphan rock and strata can not only cause ground collapse and deviation of the shield machine from the excavation trajectory, but also lead to severe wear of the shield machine cutterhead. This paper takes the treatment of bedrock and boulders in a certain interval in Fuzhou as an example. From the geological conditions of the interval, the hazards of bedrock and orphan rock, the main reasons for the formation of bedrock and orphan rock, blasting parameter design and main process parameters, blasting based on five aspects of effect, the blasting treatment methods of bedrock and orphan rock are analyzed. A reasonable blasting plan and optimal borehole spacing parameters were proposed, effectively addressing the impact of high-strength bedrock and orphan rock in composite strata on shield tunneling construction.