毫秒延时爆破振动叠加作用的数值模拟研究

NUMERICAL SIMULATION RESEARCH ON VIBRATION SUPERPOSITION EFFECTS IN THE MILLISECOND DELAY BLASTING

首先进行了单孔爆破地震波数值模拟,其波形变化规律与相关研究相吻合。在此基础上进行了两孔延时间隔为0～25ms的爆破振动波形叠加作用的数值模拟,并讨论了两种不同延时间隔理论的可行性和实用性。研究表明,即使延时间隔不足1/5倍主震周期,毫秒延时爆破的振速也低于齐发爆破的振速;当延时间隔约为1/2倍主震周期时,存在部分测点振速低于单孔爆破振速的现象,但由于爆破振动周期不规则变化,其降振的可靠性不高;当延时间隔大于地震波持续时间时,可避免前后地震波主震段叠加,从而将多孔毫秒延时爆破振速降低至单孔爆破的振速。

First of all, the single-hole blasting seismic wave was analyzed by numerical simulation meth- od, the change law of its wave shape corresponded with the relative researches. Based on the single-hole blasting vibration analysis, milliseccnd blasting vibration wave-shape superposition effects were simulated with delay time intervals between 0 and 25 milliseconds, the feasibility and practicality of two different de- lay time interval theory were discussed. The results showed that vibration velocity caused by millisecond delay blasting was lower than that caused by simultaneous blasting, even though the delay time interval was less than 1/5 of main quake period, vibration velocities of partial measuring points caused by millisec- ond delay blasting were lower than those caused by single-hole blasting when the delay time interval was nearby 1/2 of main quake period, the reliability of decreasing vibration was not high because of the irregu- lar vibration period; and the superposition of main quake segments was avoided when the delay time inter- val was longer than the duration of seismic wave so as to make vibration velocity caused by holes millisec- ond delay blasting reduce to the vibration velocity caused by the single-hole blasting.