多工艺开挖方法在运营公路隧道泄水洞施工横洞中的应用研究

Application of Multi-Process Excavation Method in the Construction of a Transverse Drainage Tunnel Near a Highway Tunnel with Active Traffic

运营公路隧道突水处理可采用在隧道外侧新建泄水洞的方案,利用泄水洞将地下水“截流”后引排。为加快施工进度,通常利用半幅运营隧道作为施工通道,并在运营隧道内施作施工横洞的方法增加泄水洞开挖断面。如果施工横洞处围岩强度大,机械开挖困难时,需采用钻爆法开挖。但是传统钻爆法开挖会产生强烈的爆破振动,对既有运营隧道安全造成影响。提出一种既有运营公路隧道泄水洞施工横洞分区分段爆破开挖的施工工艺,能够解决在高强度围岩泄水横洞开挖时的功效低、爆破振动大、施工安全风险高的问题。

Constructing a drainage tunnel next to the highway tunnel with active traffic to “collect” the groundwater can effectively minimize the groundwater inrush in the operating tunnel. To expedite the drainage tunnel construction, part of the active highway tunnel could be utilized as the construction access as well as the multi-process drainage tunnel excavation faces. The blasting excavation is a commonly used tunnel construction method in the high strength rock mass where the machine excavation is not efficient. However, the excessive vibration induced by the blasting excavation might adversely affect the safe operation of the existing highway tunnel. In tis paper, a new segmental blasting method is proposed to resolve the low efficiency, high vibration and potential safety hazards in the conventional blasting excavation method.