【摘要】 采用水封爆破进行隧道掘进时,不同水介质比和装药结构对爆破效果影响显著。基于Starfield迭代法,推导了水封爆破时炮孔孔壁冲击压力的理论计算公式。采用数值模拟,进一步研究了水封爆破时不同装药结构对孔壁冲击压力的影响和围岩的损伤特征。基于最优装药结构,进行了现场爆破试验。研究表明:不同水介质比下,孔壁压力的变化规律相似,呈先增大、后减小、最后趋于稳定的变化趋势。其中,孔壁压力在装药段最大;且随着与炸药和水介质交界面距离的增大,孔壁压力逐渐减小。水介质的存在可以减缓爆炸应力波的衰减,提高炸药能量的利用率。随着水介质比的增大,围岩损伤逐渐降低。水介质比介于0.2～0.3时,可有效提高破岩效率。相比于孔口水间隔装药与孔底水间隔装药,两端水间隔装药爆破后岩体破碎均匀,爆破效果良好。更多还原

【Abstract】 When water-sealed blasting is used in tunnel excavation, different water medium ratios and charging structures have a significant impact on the blasting outcomes. Based on the Starfield superposition method, a theoretical calculation formula for the impact pressure on the blasting hole wall during water-sealed blasting was derived. Numerical simulation was used to further study the influence of different charging structures on the impact pressure on hole walls and the damage characteristics of surrounding rock in water-sealed blasting. Field blasting tests were conducted based on the optimal charging structure. The results indicate that the variation of hole wall pressure is similar under different water medium ratios, showing a trend of first increasing, then decreasing, and finally stabilizing. The hole wall pressure is the highest in the charging section. And as the distance between the hole wall and the interface between the explosive and water medium increases, the hole wall pressure gradually decreases. The presence of water medium can slow down the attenuation of explosive stress waves and improve the utilization efficiency of explosive energy. As the water medium ratio increases, the damage to the surrounding rock gradually decreases. When the water medium ratio is between 0. 2 and 0. 3, it can effectively improve the rock breaking efficiency. Compared with the water interval charges at the orifice and bottom of the hole,the water interval charges at both ends result in uniform rock fragmentation and good blasting outcomes after blasting.更多还原