起爆方式对台阶爆破根底影响的数值模拟分析  

Numerical Simulation Analysis of Influence of Different Detonation Methods on Bedrock in Bench Blasting

作　　者：刘亮[1,2] 郑炳旭[3] 陈明[1,2] 宋锦泉[3] 王高辉[1,2] 严鹏[1,2] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,武汉430072 [2]武汉大学水工岩石力学教育部重点实验室,武汉430072 [3]广东宏大爆破股份有限公司,广州510623

出　　处：《爆破》2015年第3期49-54,78,共7页Blasting

基　　金：国家重点基础研究发展计划(2011CB013501);国家自然科学基金面上项目(51279146)

摘　　要：在台阶爆破中,根底率是评价爆破效果的一项重要指标。根据爆前、爆后岩体声波降低率,计算爆后保留岩体的损伤大小,确定临界破碎状态对应的损伤阈值。基于LS-DYNA的二次开发爆破损伤模拟技术,采用拉压损伤模型,对台阶爆破不同起爆点位置的爆破损伤效应进行数值模拟,并重点比较正向起爆和反向起爆条件下,相邻炮孔之间爆破根底的分布情况。模拟结果表明:起爆点位置能够影响能量和应力的分布状态,导致不同的爆破效果,正向起爆对孔底岩体有较好的破碎效果,能够有效地消除爆破根底,提高爆后台阶面的平整度。In bench blasting, rock toe rate is an important evaluation index of blasting effects. The damage threshold of critical breakage is ascertained by acoustic characteristics of damaged rock masses before and after blas- ting ,which is used to analyze the outline of rock foundation. The numerical simulations of bench blasting at different initiation points are implemented based on secondary development of LS-DYNA with a tensile compressive damage model. The damage spatial distribution characteristics of different initiation methods are compared, and the flatness of bedrock is analyzed with colorful nephograms of damage distributions from top and bottom initiation methods. The re- sults of numerical simulations show that different initiation points play a great influence on the stress and energy dis- tributions in blasting progress and induce different blasting effects. Top initiation turns out to be the better to decrease rock toe ratio and increase the flatness of bench floor.

关 键 词：爆破根底 起爆方式 数值模拟 爆破损伤 

分 类 号：TD235.3[矿业工程—矿井建设]