龙滩水电站右岸导流洞开挖爆破实践

Excavation Blasting for Diversion Tunnel at the Right Bank of Longtan Hydropower Station

广西龙滩水电站右岸导流洞为一特大断面隧洞 ,在高度上分上、中、下三层进行爆破开挖。上层用凿岩台车钻孔 ,中间导洞先进 ,周边光爆。中层深孔爆破 ,边墙预裂。下层主爆区深孔爆破 ,两侧预留光面层 ,浅孔光爆 ,底板保护层进行水平预裂。爆破方法多样 ,达到了安全、高效。

The diversion tunnel at the right bank of Longtan Hydropower Station is a special large bore tunnel, so the excavation was implemented in three levels (upper, medium ,lower levels). The drilling was performed by a jumbo truck in the upper level, the smooth blasting, deephole blasting and splitting blasting were adopted afler drilling in the medium level, and the deep hole was performed in the main explosive area of lower level then the short hole smooth blasting was used to prepare the horizontal presphit in the bottom protective layer.The multiple blasting methods were used to achieve the goals of safety efficiency and economy.