地下厂房顶拱层开挖施工技术

Excavation Construction Technology for Top Arch Layer of Underground Powerhouse Roof

地下厂房的开挖难点普遍在于顶拱层开挖、岩锚梁层开挖、基坑层开挖等.主要介绍缙蓄项目地下厂房顶拱层开挖,考虑大跨度顶拱围岩稳定安全、施工效率、施工便利、经济等多方面,参照类似工程经验,采取专家组意见,将开挖方法定为先导洞后扩挖的方式,中导洞及左右半幅错距开挖,周边孔采用光面爆破,降低了围岩的扰动,保证了施工进度和开挖质量,安全监测成果表明,顶拱安全处于受控状态.

The excavation difficulties of underground power plants generally lie in the excavation of the top arch layer,rock anchor beam layer,and foundation pit layer.This paper mainly introduces the excavation of the arch layer on the roof of the underground plant building in the Jincun project.Considering the stability,safety,construction efficiency,convenience,and economy of the surrounding rock of the large-span arch,and referring to similar engineering experience,this paper adopts the method of first pilot tunnel and then expanding excavation for excavation,with the middle pilot tunnel and left and right half staggered excavation,and the surrounding holes using smooth blasting.It reduces the disturbance of surrounding rock and ensures construction progress and excavation quality.The safety monitoring results indicate that the safety of the top arch is under control.