唐家山堰塞湖泄洪洞进口预留岩埂拆除爆破

Explosive Demolition for Reserved Intake Rock-dyke of Spillway Tunnel at Tangjiashan Barrier Lake

针对唐家山堰塞湖泄洪洞进口预留岩埂爆区周边环境复杂、施工工期短等难题,介绍了预留岩埂拆除爆破方案、钻爆参数设计,爆破网路布置和安全防护措施。采用GPS RTK与数字测深仪相结合的水下地形测量技术和"先减高削薄预拆除,再关闭检修闸门往堰内充水平压后一次爆除"方案,较好的解决爆渣拥堵、飞石破坏等问题,确保岩埂拆除安全准爆。预拆除后岩埂拆除方量约1000 m3,平均炸药单耗1.34 kg/m3,最大单响药量按43.2 kg控制;清渣完毕后,基槽底部开挖高程达到设计高程705 m,爆破效果比较理想。

According to the construction problems for reserved intake rock-dyke of spillway tunnel at Tangjiashan Barrier Lake, the blast scheme, blast parameters, blast network and blasting safety measures of explosive demolition are introduced. Combining GPS RTK with underwater topographic survey technology, employing ＂first reduce height and cut thin, then close bulkhead gate to balance water pressure,last explosive demolition ＂ scheme, ensures explo- sive demolition success. The volume of rock-dyke is about 1000 m3 after preliminary demolition, the average specific charge is 1.34 kg/m3 , and the maximum charge amount per delay interval is 43.2 kg. The bottom of base excavation height reaches 705 m which satisfies the design requirement after slag-removing finished, explosive effect is satisfac- tory.