岩锚吊车梁基础开挖爆破方案的设计优化与实施

在三板溪水电站地下厂房岩锚梁基础开挖过程中 ,根据不同部位围岩的结构特征 ,适时调整光爆孔的方向、间距和倾角 ;采用分区、分步开挖方法 ,并通过现场试验确定了优化的开挖方案和爆破参数。自制标准样架的采用 ,保证了光爆孔的凿岩精度。测量结果表明 ,岩台面不平整度小于 7cm ,半孔率达到 95 %以上 ,岩台成型质量达到设计要求。

OPTIMIZATION AND IMPLEMENTATION OF BLASTING PLAN FOR EXCAVATION OF ROCK BASE FOR CRANE BEAM

In excavation of rock base for crane beam in underground room of Sanbanxi Hydropower Station,the direction,spacing and inclination of smooth blasting holes were adjusted timely according to the characteristics of geological discontinuities,the zoning and stepping excavation was used and the optimal excavation scheme and blasting parameters were determined through site tests.The self-made standard guide support was used to ensure the precision of drilled smooth blasting holes.The results of measurement show that the roughness of rock bench surface is less than 7 cm and the half-cast factor is up to 95%,the quality of formed rock bench being in (agreement) with design desire.