不同堵塞条件下硬岩隧道直眼掏槽破岩效果数值模拟研究  

Numerical Simulation Study on Rock Breaking Effect of Burn Cut in Hard Rock Tunnel Under Different Blocking Conditions

作　　者：陈思佑 姚颖康 朱丹 孙金山 贾永胜 CHEN Siyou;YAO Yingkang;ZHU Dan;SUN Jinshan;JIA Yongsheng(State Key Laboratory of Precision Blasting,Hubei Key Laboratory of Blasting Engineering,Jianghan University,Wuhan 430056,Hubei,China;Wuhan Explosion&Blasting Co.,Ltd.,Wuhan 430056,Hubei,China)

机构地区：[1]江汉大学省部共建精细爆破国家重点实验室,爆破工程湖北省重点实验室,湖北武汉430056 [2]武汉爆破有限公司,湖北武汉430056

出　　处：《江汉大学学报（自然科学版）》2024年第3期5-15,共11页Journal of Jianghan University：Natural Science Edition

基　　金：湖北省重点研发计划项目(2021BAD004);中国国家铁路集团有限公司科技研究开发计划项目(K2021G024)。

摘　　要：为研究不同堵塞材料及堵塞长度对硬岩隧道直眼掏槽爆破效果的影响,依托工程实例,采用ANSYS/LS一DYNA仿真模拟软件建立三维数值模型,对5种不同堵塞条件展开研究。根据数值模型计算结果,对掏槽区域爆破裂纹拓展情况进行了定性分析,对典型部位的岩石受力情况进行了定量分析。结果表明:1)自由面岩石主要受拉应力作用产生裂纹,炮孔堵塞使得爆炸荷载整体作用时间延长,致使自由面上裂纹更加密集;2)位于炸药和堵塞材料之间空气段附近的围岩,先受爆炸应力波作用岩石被压碎,后受力在拉压应力之间多次转化,致使裂纹被放大,结合爆生气体发挥的“气楔”作用,使得裂纹几乎贯穿模型截面;3)炮孔堵塞后炸药段周围岩石受到的爆生气体作用应力值显著提升,比不堵塞时的炸药段周围岩石峰值应力高出1.31~2.34倍,炮孔堵塞使得爆生气体持续稳定发挥作用时的压应力值提高3.70~4.70倍;4)以黏土和水作为堵塞材料时,堵塞长度为40cm的直眼掏槽破岩效果优于堵塞长度为60cm的效果。研究成果可为优化硬岩隧道直眼掏槽爆破参数提供理论基础。In order to study the effect of different stemming materials and stemming lengths on the burn cut blasting of hard rock tunnels,based on engineering examples,a three-dimensional numerical model was established using ANSYS/LS-DYNA simulation software to compare and analyze five different blockage conditions.Based on the numerical model calculation results,qualitative analysis was conducted on the expansion of blasting cracks in the cutting area,and quantitative analysis was conducted on the stress situation of typical rock parts.The results indicate that,firstly,the free surface rock is mainly subjected to tensile stress to generate cracks,and the blockage of the blast hole prolongs the overall action time of the explosion load,resulting in a denser number of cracks on the free surface.Secondly,the surrounding rock near the air section between the explosive and the stemming material is first crushed by the explosive stress wave and then subjected to multiple transformations between tensile and compressive stresses,causing the crack to be amplified.Due to the″gas wedge″effect of the explosive gas,the crack almost penetrates the model cross-section.Thirdly,after the blockage of the blast hole,the stress value of the explosive gas acting on the rocks around the explosive section is significantly increased,which is 1.31-2.34 times higher than the peak stress of the rock around the explosive section when it is not blocked.The blockage of the blast hole increases the compressive stress value of the explosive gas when it continues to play a stable role by 3.70-4.70 times.Finally,when using gun mud and water as blockage materials,the rock-breaking effect of a burn cut with a stemming length of 40 cm is better than that of a burn cut with a stemming length of 60 cm.The research results can provide a theoretical basis for optimizing the parameters of burn-cut blasting in hard rock tunnels.

关 键 词：钻爆法 硬岩隧道 直眼掏槽 炮孔堵塞 数值模拟 

分 类 号：TD235[矿业工程—矿井建设]