精确延时爆破条件下的边坡振动响应特性

精确延时条件下的爆破振动响应特性是当前工程爆破领域的重点研究内容。基于岩质边坡爆破振动响应的理论分析,结合溪洛渡水电站边坡开挖爆破振动的数值模拟,研究了精确延时条件下的岩质边坡爆破振动响应特性。结果表明,在边坡的爆源近区,质点峰值振动速度及第一主应力的变化随延时时间的不同具有明显的低峰值,而在爆源远区,则难以确定明确的变化规律。在爆源的近区,合理的延时时间可以降低甚至避免振动效应叠加,该延时时间的最小值约为爆破振动的主周期;爆源的远区,虽然振动峰值降低,但是难以避免爆破振动叠加效应。

ANALYSIS OF VIBRATION RESPONSE OF ROCK SLOPE UNDER ACCURACY TIME-DELAY BLASTING

Response characteristic of blasting vibration under the condition of accurate time-delay blasting is an important research content in the field of engineering blasting.Basing on the theoretical analysis of response characteristic of blasting vibration of rock slope,and combining with numerical simulation of slope excavation blasting vibration of Xiluodu hydropower station,response characteristic of blasting vibration under the condition of accurate time-delay was studied.The results indicated that in the near field of explosion source of slope,peak particle vibration velocity and the change of first principal stress had obvious low peak value following different time-delay,and reasonable time-delay could reduce or even avoid the effect of vibration superposition,the minimum delay time which was as much as the value of principal period of blasting vibration.By comparison,in the far field of explosion source of slope,it was rather difficult to explicitly identify the change laws,although vibration peak value was decreased,it was difficult to avoid the effect of blasting vibration superposition.