观音岩水电站导流底孔出口围堰爆破拆除技术

观音岩水电站导流底孔出口围堰紧邻永久建筑物，导流底孔施工完成后，围堰爆破拆除可能对周边永久建筑物产生影响。为了保证周边建筑物在爆破拆除时的安全，分析了爆破拆除的控制难点，设计采用了松动爆破、布置防振孔切割爆破、定向爆破、冲击锤人工风镐凿除、建筑物遮盖防护等措施，降低了建筑物爆破的振动速度，控制了爆破飞石的距离，有效保护了周围永久建筑物的安全。爆破设计及施工经验可供类似工程设计施工参考。

Blast demolition technology of cofferdam of diversion bottom outlet of Guanyinyan Hydropower Station

The cofferdam of diversion bottom outlet of Guanyinyan Hydropower Station is immediately adjacent to some permanent structure and the blast demolition of the cofferdam after the completion of the diversion bottom outlet construction will probably affect the safety of the structures. In order to ensure the safety of the surrounding structures, the difficult points of blast demolition control were analyzed and the measures such as loose blast, anti-vibration hole for cut-blasting, directional blasting, excavating by percussion hammer and artificial pneumatic pick, structure covering were taken, which reduced the blast vibration velocity, controlled the flying distance of blasted stone and effectively protected the safety of the surrounding structures. 