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互层状围岩隧道切槽爆破破岩规律研究
Rock Fragmentation Patterns in Tunnels with Interbedded Surrounding Rock by Blasting with Slotted Blastholes
【摘要】 根据互层状围岩与周边孔的相对位置关系,对围岩互层面与两邻近周边孔连心线相对位置关系进行分类;采用LS-DYNA数值模拟方法,探究典型工况(围岩互层面与炮孔连心中垂线重合)下,互层面对孔间围岩爆破裂纹扩展的影响机理;并对围岩互层面与炮孔连心线不同相对位置关系下,围岩互层面对孔间围岩爆破成形效果的影响进行了研究。结果表明,砂岩中的爆破振动波传播速度略高于砂质泥岩中的传播速度;爆破荷载下,较软岩层和互层面上围岩受损严重;两炮孔爆破振动波峰叠加加剧了围岩损伤;互层面贯穿炮孔时爆破效果欠佳,互层面位于炮孔连心中垂线时爆破效果较理想。
【Abstract】 According to the relative position between interbedded surrounding rock and the peripheral holes, the relationship between bedding planes and the connecting line of the adjacent blastholes was classified into three kinds. Mechanism for bedding planes bringing impact to crack propagation in rocks between blastholes by blasting under typical work conditions(with bedding planes on the perpendicular bisector of the connecting line of blastholes) was explored by the LS-DYNA numerical simulation; and the effect of bedding planes in a different relative position to the connecting line of blastholes on the blasting effect of surrounding rock was also studied. It is found that the propagation speed of blasting vibration waves in sandstone is slightly higher than that in sandy mudstone. Under blasting loads, the surrounding rock above both softer layer and the beddings suffer severe damage. The superposition of two-blasthole blasting vibration wave peaks intensifies the damage to the surrounding rock. The blasting effect is poor when the bedding plane penetrates the blastholes, but the blasting effect is ideal if the bedding plane is on the perpendicular bisector of the connecting line of blastholes.
【Key words】 tunnel blasting; interbedded surrounding rock; blasting with slotted blasthole; crack propagation; bedding plane; peripheral hole; blasting vibration; surrounding rock damage;
- 【文献出处】 矿冶工程 ,Mining and Metallurgical Engineering , 编辑部邮箱 ,2024年06期
- 【分类号】U455;U451.2
- 【下载频次】25