提高堆石坝过渡料细颗粒含量的措施

摘要

堆石坝过渡料对垫层料具有反滤保护作用，其细颗粒含量是评价过渡料级配优劣的重要指标。结合Kuz-Ram爆破块度预测模型，分析了影响过渡料细颗粒含量的主要因素，并在长河坝过渡料开采爆破试验的基础上，总结了提高细颗粒含量的工程技术措施。爆破试验表明，选用爆速较高的炸药、适当减小炮孔间排距、选择合理的装药结构以及合适的起爆时差等措施，能够有效提高堆石坝过渡料的细颗粒含量，使由爆破开采获得的过渡料能直接上坝填筑，节省工程投资。%In rock-fill dams, the transition material plays a role of filtration-prevention for the cushion material, and the fine particle content is an important assessing indicator for the gradation quality of transition material. Based on the Kuz-Ram size prediction model for explosion blocks, we analyze the influential factors to the fine particle content. And on the basis of the explosion tests in mining of transition material at Changheba Hydropower Station, we summarize the main technical measures in-creasing the fine particle content. The explosion test shows that the following measures could effectively increase the fine particle content in mining process of transition material, namely adopting high detonation velocity explosive, reducing the interval space of blasting holes moderately, selecting rational charging structures and adopting rational ignition time-differences. By adopting the presented measures, we could use the blasted stones as transition material directly, saving engineering cost effectively.