不耦合空气间隔装药结构爆破机理分析  

Blasting Mechanism of Uncoupled Air Interval Charge Structure

作　　者：董源 何艳飞 马晨阳 刘美山[1] DONG Yuan;HE Yanfei;MA Chenyang;LIU Meishan(Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China;Xinjiang Water Conservancy Development and Construction Group Co.,Ltd.,Urumqi 830000,China)

机构地区：[1]长江科学院水利部岩土力学与工程重点实验室,武汉430010 [2]新疆水发建设集团有限公司,乌鲁木齐830000

出　　处：《长江技术经济》2024年第4期104-112,共9页Technology and Economy of Changjiang

摘　　要：空气间隔装药爆破广泛应用于隧道掘进开挖,其中不耦合系数是保证光面爆破效果的关键因素。QBT工程现场仅有Φ32 mm直径的药卷,为改善爆破效果,采用LS-DYNA程序对轴向不耦合系数Kl进行数值研究,分析了轴向不耦合系数Kl取2.41、3.22、4.83时炮孔壁应力场、速度场及损伤特性,与光面爆破小直径药卷(Φ25 mm)连续装药结构进行对比,揭示轴向不耦合系数对爆破效果的影响,得到最优取值。结果表明:有效应力峰值与轴向不耦合系数成反比,应力衰减程度与轴向不耦合系数成正比;质点峰值速度下降率为64%~82%,有效降低了爆破振动,轴向不耦合系数越大,控制振动水平能力越强,但由于岩石损伤程度分布发育不充分,在孔口处可能存在挂门帘现象。Air interval charge blasting is widely used in tunnelling,with the non-coupling coefficient as the key factor to ensure smooth blasting effect.Given that the QBT project site utilizes merely a 32 mm diameter cartridge,we conducted numerical investigation by using LS-DYNA program to enhance the blasting effect.The study focused on the axial uncoupling coefficient Kl and analyzed the stress field,velocity field and damage characteristics of the blast hole wall with Kl values of 2.41,3.22 and 4.83.We further compared the findings with those obtained from continuous charge structure with a small diameter cartridge(25 mm)in smooth blasting.This comparison revealed the influence of Kl on blasting effect and suggested the optimal value of Kl.The results show that peak effective stress is inversely proportional to K_(l),while the degree of stress attenuation is directly proportional to Kl.Particle peak velocity decreased by a rate of 64%-82%,effectively reducing blasting vibration.Larger K_(l) enhances the ability to control the vibration.However,insufficient distribution of rock damage may result in“curtain-like rock residues”at the borehole entrance due to incomplete fragmentation.

关 键 词：光面爆破 空气间隔装药 不耦合系数 数值模拟 

分 类 号：TU456[建筑科学—岩土工程]