爆炸堵孔装置在直眼掏槽中的应用

Application of Explosive Stemming Apparatus in Burn Cut Blasting

为了评估爆炸堵孔装置的堵塞效果,将装有导爆索的爆炸堵孔装置放入模拟炮孔中进行爆炸实验,然后通过万能试验机对其进行单轴压缩脱模实验。结果表明:爆炸堵孔装置与孔壁贴合后的抗压强度为26.5~35 MPa,抗剪强度为3.07~3.4 MPa,远大于常规炮泥的抗剪强度(0.09 MPa)。将爆炸堵孔装置用于隧道爆破直眼掏槽眼中,并对原有的孔网参数进行优化,结果显示:在保证掏槽进尺的情况下,掏槽眼孔数相对于优化前减少了35%,而且炮孔的间距也相应增大,有利于降低相邻掏槽孔贯穿的风险,从而有效提高施工效率。因此,将爆炸堵孔装置与炮泥联合使用,可大幅增强炮孔堵塞效果,从而防止爆生气体过早逸出,延长爆生气体在炮孔内的作用时间,进而充分发挥爆生气体的气楔破岩作用,并有效增强爆生气体的抛掷作用,对保证隧道直眼掏槽爆破效果具有重要意义。

A kind of explosive stemming apparatus with detonating cord was placed in a simulated blast hole to evaluate its blocking effect,and then a uniaxial compression test was performed on it using a universal testing machine.The result showed that the compressive strength of the explosive stemming apparatus after being in contact with the blast hole wall was 26.5~35 MPa,and the shear strength was 3.07~3.4 MPa,which was much higher than the shear strength of conventional stemming materials(0.09 MPa).The explosive stemming apparatus was applied on cut blast in tunnel excavation together with optimizing the original blast hole layout.It turned out that the number of cut holes reduced by 35%compared to before optimization while maintaining the same excavation depth,and the hole spacing increased accordingly,which reduced the risk of piercing adjacent cut holes and effectively improved construction efficiency.Therefore,combining the explosive stemming apparatus with stemming material can greatly enhance the blocking effect and prevent premature gas escape.This effect can further extend the gas action duration in the blast hole,and improve the throwing effect of explosion gases by fully exerting the gas wedge rock breaking effect.