岩巷掘进中角柱形掏槽孔合理间距的分析与应用

Analysis and application of reasonable spacing of corner column cut holes in rock roadway excavation

为了提高岩巷掘进效率,对掏槽孔合理间距进行研究与分析,以便于爆破方案设计中掏槽孔间距的选择。从角柱形掏槽入手,结合补偿空间理论和柱形药包爆破机理,推导出最适孔间距的数学计算模型,得出175 mm为理论最适间距。结合理论推导和数值计算对岩巷掘进中角柱形掏槽孔的合理间距进行了分析,发现170 mm孔间距的模型爆破效果最好,且有效应力随着间距的改变先减小后增大,最适间距出现在有效应力最低处。结合数值计算和现场施工效果综合分析,发现采用最适间距的爆破方案能够使平均爆破进尺增加0.7 m,每循环消耗炸药量降低2.66 kg,振速平均降低0.12 cm/s,新方案大大降低了爆破用材,提高经济效益和掘进效率,并且减少了振动带来的危害。研究结果可为角柱形掏槽爆破参数设计提供参考,对类似施工条件的爆破方案设计具有一定的参考价值。

In order to improve the efficiency of rock roadway excavation,the reasonable spacing of the cut holes is studied and analyzed,so as to facilitate the selection of the cut hole spacing in the blasting scheme design.Starting from the corner cylindrical undercut,combined with the compensation space theory and the blasting mechanism of the cylindrical charge,the mathematical calculation model of the optimum hole spacing was deduced,and it was concluded that 175 mm was the theoretical optimum spacing.Combined with theoretical derivation and numerical calculation,the reasonable spacing of corner-column cut holes in rock roadway excavation was analyzed.It was found that the model with a hole spacing of 170 mm had the best blasting effect,and the effective stress first decreased and then increased with the change of spacing.The proper spacing occurs where the effective stress is lowest.Combined with numerical calculation and comprehensive analysis of on-site construction effects,it is found that the blasting plan with the optimum spacing can increase the average blasting footage by 0.7 m,reduce the consumption of explosives per cycle by 2.66 kg,and reduce the vibration speed by an average of 0.12 cm/s.The new plan greatly reduces the The blasting material improves economic efficiency and excavation efficiency,and reduces the harm caused by vibration.The research results can provide a reference for the design of blasting parameters for corner-column undercuts,and have a certain reference value for the design of blasting schemes with similar construction conditions.