聚能管爆破参数对周边爆破效果的影响

Influence of Slotted Pipe Blasting Parameters on Surrounding Blasting

在巷道施工过程中,周边爆破是非常重要的环节,使用聚能管爆破来提升周边爆破的效果是一种常见的方式。但是聚能管爆破的诸多参数设置不合理,仍然会使得周边爆破的定向破坏效果不明显,轮廓线受破坏较大,炮孔留存度低和超欠挖的现象。为了进一步提高爆破损伤的方向性,改善爆破质量,需要对聚能爆破的参数进行优化,达到更好的施工效果。使用ANSYS/LSDYNA进行数值模拟实验,从炸药-聚能管耦合性与不同的应力波相遇位置这两个方面进行研究,寻找相对应的合理爆破参数。对数值模拟结果进行分析,当炸药与聚能管之间的不耦合系数为1.12时可以在保护围岩岩体与定向破坏之间取得平衡。改变相邻两组炸药的起爆位置,使得同一水平面上的爆炸引力波相遇位置偏移至两炮孔之间3/4的位置时,轮廓线的完整程度得到了较大程度的提高。通过这一系列结果可以得出在聚能管与药卷之间采用不耦合结构,根据聚能管大小采用合适的药卷,并通过改变炸药的起爆位置使得炮孔之间的应力波相遇的位置发生改变,可以较大幅度地降低对留存岩体的损害。对这两个研究较少的参数进行优化,从更广的角度对爆破效果进行提高,使隧道巷道工程获得更好的轮廓线效果与炮孔完整度,降低超欠挖。

Perimeter blasting is very important to control engineering quality in the process of roadway construction,and it is a common way to use slotted pipe blasting to improve the perimeter blasting effect.However,the unreasonable setting of slotted pipe blasting parameters still weakens the directional destruction effect,including the greatly damaged contour,low hole retention rate,common phenomena of over-excavation and under-excavation.In order to improve the directionality of blasting damage,the slotted pipe blasting parameters should be optimized.The reasonable blasting parameters were determined with the study of explosive slotted pipe uncoupling and different initiation positions by numerical simulation using ANSYS/LSDYNA.According to the numerical simulation results,the balance between the protection of surrounding rock mass and directional failure can be achieved when the uncoupling coefficient between the explosive and slotted pipe is 1.12.Meanwhile,the integrity of the contour line is greatly improved when the initiation positions of two adjacent explosives are changed to make the meeting position of the explosive shock waves on the same horizontal plane that shifted to 3/4 of the position between two blast holes.It can be concluded that the damage to the retained rock mass can be greatly reduced as adopting uncoupled structure between slotted pipe and charge,and changing the meeting position of stress wave between blast holes by adjusting the detonation position of charge.