灰色关联分析在降低爆破地震效应中的应用

Application of grey correlation analysis to reducing the effect of the blasting seism

灰色关联分析方法可对各影响因素重要程度进行量化比较,为降低爆破地震效应提供依据。首先对灰色关联分析的原理和灰色关联矩阵的计算进行分析,然后以岩体完整性系数为标准,将爆破地震波传播途径的地质条件进行量化并分为5类,以距离、总药量、单段最大药量、段数、微差延时、爆破方向、高程差、地质条件为相关因素变量,以峰值振速、主振频率、持续时间为系统特征变量,并从爆破试验结果中选取9组数据作为分析样本进行灰色关联矩阵计算。结果表明,影响爆破地震效应因素的主次顺序为距离、单段最大药量、总药量、微差延时、爆破方向、高程差、段数、地质条件,距离和单段最大药量起决定性作用。依据研究结果提出了降低单段最大药量、选择合适微差延时、调整爆破方向和改变地质条件4项降低峰值振速的措施。在爆破验证试验中采取了降低单段最大药量,调整爆破方向和改变地质条件3项措施。测试结果表明,采取措施后监测点A点和B点的峰值振速分别降低了12.16%和15 15%,主振频率和持续时间略微减小,降振措施是有效的。

This paper likes to introduce its authors＇ study on how to reduce the seismic effect of the engineering blasting on its surrounding areas by using the gray correlation analysis method. For our research purpose, first of all, we have briefly introduced the principle of gray correlation analysis and the calculation of gray correlation matrix in this paper. And, next, while taking the rock mass completeness modulus as a standard, we have divided the geological conditions that the blasting seismic waves pass througb into five categories, that is, distance cover, total quantity of dynamite, single-stage maximum quantity of dynamite, the number of sections, time of millisecond delay, blasting direction, elevation difference and geological condition as related factor variables; the peak velocity, main frequency and vibration duration as system characteristic variables; the nine groups of data as swatch that are selected from the blasting experiments taken in Nanning. Based on the mentioned research results we have brought forth four measures for vibration absorption, that is, reducing the single-stage maximum quantity of dynamite, selecting appropriate time of millisecond delay, adjusting blasting direction and, last of all, changing the geological condition. Our testing results indicate that the peak：velocity of point A can be decreased by 12.16%, whereas that B point can be reduced by 15115% . With the main frequency and vibration duration reduced appreciably, all the vibration absorption measures we have taken prove to be correct and effective.