爆破振动持时分析及微差爆破延期时间优选

Analysis of blasting vibration duration and optimizing of delayed time interval for millisecond blasting

爆破振动持续时间以及微差爆破延期时间分别是爆破振动危害客观评价与主动控制的重要指标,对振动持时影响因素和延期时间优选方法进行深入探究极为必要。结合量纲分析理论,探讨了爆破振动持时影响因素,推导出爆破振动持时预测公式,该公式线性相关性达到89.7%;基于地震波线性叠加原理,通过MATLAB 7.0编程,计算得到毫秒微差爆破不同爆心距处合理延时区间。结果表明,爆破振动信号能量与振动持续时间相关性高,在振动持时预测公式中引入信号能量,可提高预测精度;振动持续时间与比例速度负相关,与比例药量正相关;合理孔间延期时间往往不是某一具体值,而是一个或多个时间区间;不同爆心距处合理延期时间值不同。工程应用表明,给出的爆破振动持时预测公式与微差爆破延时优选方法切实可行。

Duration of blasting vibration and delayed time interval of millisecond blasting are respectively an important indicator for assessing and controlling blasting hazards.It is therefore of great necessity to explore the factors that may influence the duration and the ways that can optimize the interval.In the present work,combined with dimensional analysis,we examined the factors influencing the duration arrived at a formula for predicting the blasting vibration duration,whose linear correlation reached 89.7%.Based on the linear superposition theory of seismic wave,the reasonable range of delayed time interval with different distances between the blasting source and the measuring point was obtained using MATLAB7.0.The result shows that there is close correlation between the signal energy and the duration of blasting vibration,the accuracy of prediction can be improved by introducing the signal energy into the predictive formula,the duration is negatively related to the proportional velocity and positively related to the proportional charge weight,and the reasonable range of the delayed time interval between the blasting holes is not always a specific value but may be one or more time intervals,which are determined by different distances between the explosion source and the measuring point.The application of the formula in actual engineering shows that our predictive formula and optimization for millisecond blasting are highly practicable.