岩石动态特性对爆破振动能量分布的影响

为了从爆破振动能量分布角度研究破碎能量利用问题,结合露天铁矿岩石动态特性,使用EEMD方法分析爆区磁铁矿、绿泥岩与混合岩的动态特性对振动能量分布的影响规律。结果表明：动抗拉强度与弹性模量最低的混合岩,爆破振动能量的分布最为均匀,振动能量在50 Hz以下的频带出现了分散的多个峰值,90％以上的振动能量集中在20~80 Hz；随着岩石动抗拉强度与弹性模量的减小,爆破振动能量在整体上的分布向高频发展,总能量与瞬时能量峰值均明显降低,用于岩石破碎的爆炸能量比例提升,且爆破远区振动能量分布频带增宽,有利于岩体完整性保护。

Influence of Rock Dynamic Characteristics on Distribution of Blasting Vibration

The usage of crushing energy was researched based on the energy distribution of blasting vibration. Com-bined with the dynamic characteristics of open pit mine rock, the influences of blasting vibration energy’s distribution have been analyzed using EEMD method. It could be shown from the results that the blasting vibration energy of agmatite, which has the lowest dynamic tensile strength andelastic modulus, is most evenly distributed. In principal frequencies band, mul-tiple instantaneous energy peaks appear at frequencies which are below 50 Hz. More than 90% of the vibration energy con-centrates in 20~40 Hz. With the decrease ofdynamic tensile strength and the elastic modulus, the blasting vibration energy in the far zone tends to be distributed at high frequencies overall, the vibration of energy and instantaneous energy peak values are decreased significantly, and the explosion for rock fragmentation has the maximum energy. Besides, the distribu-tion band of blasting energy in blasting far zone is broaden, which is advantageous to protect the integrity of rocks.