Characteristics Analysis and Safety Control of Deep-hole Bench Blasting Vibration in Large Open-pit Mine
In order to reduce the adverse effects of the quarry appurtenances by the blasting vibration effect,the blasting vibration monitoring was carried out in the blasbing area of Changjiu open-pit building materials mine.The propagation law and energy distribution characteristics of the blasting vibration in the quarry were studied by regression analysis and wavelet packet analysis,and the safety charge was calculated using the improved Sadowski formula considering probability.The results show that the peak vibration velocity in the three directions is larger in the horizontal radial and vertical directions and smaller in the horizontal tangential direction.The peak vibration velocity is generally proportional to the maximum single-part charge and in-versely proportional to the center-of-explosion(COE)distance.Most of the blasting vibration at the site of the main frequency of the blasting vibration for the low frequency of 20 Hz or less.Due to the use of differential delayed detonation,the section charge and differential interval time are key factors affecting the peak vibration speed.Through regression fitting to establish a mathematical model of blasting vibration propagation in line with the site geology,geomorphology and blasting conditions,in which the vertical vibration propagation of the most clear directionality.Quarrying blasting vibration energy distribution within 200 Hz,and mainly concentrated in the 90 Hz below,with the increase of the maximum single-segment charge and blast center distance,the bandwidth of the main vibration band decreases and moves to the low-frequency end,and the proportion of energy in the low-frequency band increases.The effect of increasing the number of detonator segments is not good in the near area of blasting,but obvious in the far area of blasting.By comparing the measured data,using the improved Sadowski formula consid-ering probability to calculate the safe charge can better control the occurrence of small probability events exceeding the safe vi-bration velocity limit than the traditional Sadowski formula,and effectively improve the probability of the ore pass being protec-ted in the blasting construction process,which has certain reference significance for the design of control blasting parameters.
万方数据
维普
