三板溪水电站地下厂房开挖爆破震动控制

Blasting Shaking Control of San Banxi Underground Chamber Excavation

三板溪水电站地下厂房开挖施工中,通过对支护、混凝土两个不同介质的质点振动速率对比、换算,得到了以支护为垂直距离计算爆破区药量分布的几何中心至观测点(锚杆)的距离,以此作为地下厂房相应区域爆破时需控制的爆破单响药量。同时,结合观测综合数据分析进而合理地找到了除地下厂房Ⅱ、Ⅲ层以外及以下各层的开挖爆破方法,以最小爆破震动减少对厂房高边墙的危害。

The key points of blasting in underground chamber excavation are illustrated simply in this article. Taking example for excavation control blasting of Ⅱ and Ⅲ floors, the distance from observation point to the geometry center which is used for computing explosive distribution by taking supporting as vertical distance, is got according to contrasting and conversing particles shaking velocities of two kinds of mediums, Then the dosage that should be controlled in once blasting is gained for the corresponding area blasting of the underground chamber. At the same time, by analyzing synthesis data observed, a rational excavation blasting method is found except the underground chamber Ⅱ, Ⅲ and lower floors. Operation security of bridge engines on system bolts anchored girders is ensured by minimizing the blasting danger to chamber high wall.