采用大孔径深孔梯段爆破开采堆石料

Rock-fill quarried by adoption of large deep hole blasting with gradient section

白云水电站混凝土面板堆石坝采用大孔径、小抵抗线、宽孔距深孔梯段爆破的方法开采堆石料。爆破参数为：钻孔直径１６５ｍｍ，孔间距７．０ｍ，排距４．０ｍ，钻孔倾斜度７５°（与水平面夹角），梯段高度１５．０ｍ，下部连续装药，上部间隔装药，孔口布设闭锁小药包。实践证明：利用大孔径、小抵抗线、宽孔距深孔梯段爆破，结合料场的具体地质条件，能够开采出级配良好的高坝堆石料；在孔口布置闭锁小药包，能有效地降低大块率，改善爆破料的级配；乳化炸药的使用，既能取得良好的爆破效果，还能相对降低工程成本；采用大孔径高速潜孔钻，能较大地提高堆石料的开采强度，从而充分发挥面板坝快速施工的优势。

Rock-fill for Baiyun concrete face rock-fill dam was quarried by adoption of large deep hole blasting with gradient section and long centre distance. The blasting parameters are 1 0. 165 m in diameter, 7. 0 m of centre distance,4. 0 m of distance between rows of holes, 75°of declination, and 15 m of gradient aection. Explosive was loadedcontinuously in the lower section, while alternatively in the upper section. And a small explosive package closed the entrance. This can quarry excellent graded rock-fill if it combines with quarry geological cowhtioro. The smell explosive package at the entrance can reduce the proportion of large piece of rock, and improve gtading of rock-fill.Employment of paste explosive can relatively reduce cost. Adoption of a large diameter deep hole drill can promote quarry intensity.