全断面与台阶法爆破作用下围岩的振动特征

基于现场试验和实测数据,通过量纲分析,建立了全断面爆破与台阶法爆破时岩体振动主频与单段最大药量及爆心距之间的函数关系,并进行了回归分析;通过声波试验,分析了在这两种爆破方式下,经过5次爆破作用后岩体的累积损伤规律。研究结果表明:岩体的振动主频随单段最大药量和爆心距的增加而减少,台阶法爆破比全断面爆破减少得更为迅速,而且相对于爆心距,单段最大药量对主振频率的影响更为显著;岩体在爆破作用下的损伤呈现非线性累积规律,前3次爆破对岩体损伤程度更深,且全断面爆破引起的岩体损伤较台阶法爆破更为严重。

Dynamic Response of Surrounding Rock under Full Face or Bench Blasting Excavation

Dimensional analysis was conducted on the measured data and field experiments to establish functional relationship between the main vibration frequency of surrounding rock subjected to full face blasting or bench blasting and single maximum loading or blasting distance,regression analysis was then employed to process the measured data.Acoustic study on the two blasting methods revealed the accumulative damage law of rock in five times of blasting.Results show that the main vibration frequency decreases with the increase of the maximum single charge and blasting center distance,and this decrease is much more faster in bench blasting than in full face blasting.Effect of the maximum single dose on the main vibration frequency is more significant than that of distance.It shows a nonlinear accumulative damage for rock under blasting effect.The damage is deeper at the first three blasting,and rock damage caused by full face blasting is more serious than that caused by bench blasting.