孔间微差时间的1ms时间差对爆破振动的影响

目前,在岩土工程微差爆破领域的研究方面,普遍认为3ms以内的时间差对实际工程的爆破振动效果影响不大,对这方面的研究也不够深入。为此,本文借助数值模拟和工程试验的方法,研究孔间微差时间的1ms时间差对爆破振动影响。以自由面形成原理计算孔间微差时间,并以此为依据,按1ms等间距选择了9ms、10ms、11ms、12ms、13ms、14ms、15ms共7种孔间微差延迟方案进行数值模拟,以爆破振动速度确定最优微差时间。然后,通过工程试验验证最优微差时间的爆破振动效果。数值模拟和工程试验结果表明： 1ms和2ms的误差引起爆破振动速度的变化分别达到0.9%~8.1%和2%~13%,将孔间微差时间精确到1ms级对爆破减振有明显的效果,15ms孔间微差时间的爆破振动最小,对周边建筑物影响最小,监测点振动速度符合安全要求。

The Determination of Between-holes Millisecond Time Based on Blasting Vibration

At present, in the field of millisecond blasting of geotechnical engineering, it is generally considered that delay time within 3ms has little effect on blasting vibration of practical engineering, and researches on this aspect are not thorough enough. With the help of numerical simulation and engineering test, this paper studies the effect of 1ms delay time of between-holes millisecond time have on blasting vibration. This paper uses the principle of free surface formation to calculate the between-holes millisecond time, and on this basis, seven kinds of delay schemes of between-holes millisecond are selected for numerical simulation and they are 9ms, 10ms, 11ms, 12ms, 13ms, 14ms, 15ms. The optimal millisecond time is determined by blasting vibration velocity, then, the blasting vibration effect of the optimal millisecondtime is verified by engineering test. The results of numerical simulation and engineering test show that the variation of blasting vibration velocity caused by the errors of 1ms and 2ms is up to 0.9%-8.1% and 2%-13% respectively. Correcting the between-holes millisecond time to 1ms has an obvious effect on blasting vibration reduction. The between-holes millisecond time of 15ms has the minimal blasting vibration and the least effect on surrounding buildings, and the vibration velocity of the monitoring point meets safety requirements.