露天矿破碎站基坑控界爆破技术

Boundary Controlled Blasting Technology for Foundation Pit of Crushing Station in Open-pit Mine

在深凹露天矿,会使用运输成本较低廉的胶带运输系统。因此就需要在岩石台阶中,利用爆破综合技术,在围岩损伤最小的情况下,控制开凿出符合胶带破碎机安装边界的基坑空间,这一系列技术措施可以归纳为露天矿破碎站基坑控界爆破技术。将基坑爆破开挖设计为“一次预裂成型,分层控制爆破开挖”的总施工方案。并利用能够克服“尺寸效应”的1∶1全尺寸模拟爆破设计,进行设计参数验证和优化。模拟爆破结果表明单耗为0.64 kg/m^(3)时的炸药能量偏大,导致爆堆抛掷量大,预留岩壁受损严重,且预裂孔超前主爆孔100 ms起爆的延时设计效果不佳,预裂缝拉裂效果一般。根据模拟效果进行了施工方案及参数优化,将炸药单耗降低至了0.55 kg/m^(3),同时也对预裂孔线装药密度以及爆破网路延时进行了优化,优化后的控界爆破效果要明显优于之前。

In deep open pit mine,a lower cost tape delivery system is often used.Therefore,it is necessary to use the control blasting technology to excavate a foundation space of crusher installation in the bench with minimum damage to the surrounding rock mass.The foundation blasting excavation was designed as a general construction plan of“one pre-cracking and controlled blasting excavation in layers”.The 1∶1 full-scale simulation blasting design which can overcome the“size effect”was used to verify and optimize the design parameters.The simulated blasting results show that when the unit consumption of the explosive is 0.64 kg/m^(3),which resulted in a large explosive pile throw and serious damage to the reserved rock mass,and the pre-splitting blasting delay design effect of 100 ms ahead of time is not good.The pre-splitting blasting did not completely tear the rock mass.According to the simulation results,the construction plan and parameters were optimized,and the explosive unit consumption was reduced to 0.55 kg/m.At the same time,the line charge density of the pre-split holes and the blasting network delay were optimized,and the blasting effect was obviously improved.