偏/同心不耦合非装药段孔壁压力分布规律研究

Study on the distribution of borehole pressure in uncoupled eccentric/concentric non-charged section

孔壁压力是分析爆炸载荷在隧道掘进过程中对围岩损伤破坏的重要参数,针对隧道周边孔理论装药结构为同心不耦合装药,而实际装药结构为偏心不耦合装药的问题,采用模型试验方法,研究偏心与同心不耦合装药结构爆炸非装药段的孔壁压力。结果表明:偏心装药非装药段测距在0.2 m内的同截面,上孔壁峰值压力大于下孔壁;超过0.2 m时,炮孔同截面孔壁峰值压力近似相等。测距在0.2 m内时,偏心装药非装药段上孔壁峰值压力较同心装药大,偏心装药下孔壁峰值压力较同心装药小;测距大于0.2 m时,同心装药非装药段孔壁峰值压力均大于偏心装药。偏心装药非装药段上孔壁峰值压力随测距衰减最快,下孔壁次之,同心装药孔壁峰值压力衰减最慢。研究结果可为合理设计装药结构提供参考。

Borehole pressure is an important parameter to analyze the damage and failure of surrounding rock caused by explosion load during excavation.Aiming at the problem that the theoretical charge structure of peripheral hole is concentric uncoupled charge,while the actual charge structure is eccentric uncoupled charge.Similar model test and numerical simulation were used to test the borehole pressure of eccentric and concentric uncoupled charge structure.The results show that the peak pressure of the upper hole wall is greater than that of the lower hole wall in the same section of the non-charge section of the eccentric charge within 0.2 m.When it exceeds 0.2 m,the peak pressure of the hole wall is approximately equal to that of the cross section.When the distance is within 0.2 m,the peak pressure of the hole wall in the non-charge section of the eccentric charge is larger than that of the concentric charge,and the peak pressure of the hole wall under the eccentric charge is smaller than that of the concentric charge.When the distance is greater than 0.2 m,the peak pressure of the hole wall in the non-charge section of the concentric charge is greater than that of the eccentric charge.The peak pressure of the upper hole wall of the non-charge section of the eccentric charge decays fastest with the distance measurement,followed by the lower hole wall,and the peak pressure of the concentric charge decays the slowest.The research results can provide reference for reasonable design of charge structure.