周边孔外插角对隧道光面爆破效果的影响  

The Influence of Peripheral Holes External Insertion Angle on the Smooth Blasting Effect of Tunnels

作　　者：江珊 孟海利 郭云龙 JIANG Shan;MENG Haili;GUO Yunlong(Postgraduate Department,China Academy of Railway Sciences,Beijing 100081,China;Railway Engineering Research Institute,CARS,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院研究生部,北京100081 [2]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081

出　　处：《铁道建筑》2024年第2期102-106,共5页Railway Engineering

基　　金：中国铁道科学研究院集团有限公司基金(2022YJ087)。

摘　　要：建立孔间距与外插角的关系式,分别对周边孔外插角为定值(3°)和周边孔外插角为不定值(在3°、4°、5°随机选取)两种工况隧道爆破过程进行模拟分析。结果表明:外插角变化会改变周边孔之间的空间位置关系,影响爆破应力波的分布;两种工况周边孔爆破应力波衰减速度均随距离增大由快变慢;外插角不一致时,周边孔保护侧岩体中爆破应力波在多个部位叠加增强,沿隧道开挖轮廓爆破应力不均匀分布,导致更多部位超挖,不利于形成光滑平整的隧道开挖轮廓。因此,工程实践中须要严格控制外插角。With the relationship between hole spacing and external insertion angle established,the simulations of tunnel blasting process were analyzed under the conditions of the external insertion angle at 3°and randomly selected among 3°,4°,and 5°respectively.The results indicate that changes of external insertion angle will change the spatial position relationship between peripheral holes and affect the distribution pattern of blasting stress waves.In both cases,the attenuation speed of stress waves in peripheral hole blasting decreases from fast to slow with increasing distance.When the external insertion angle is inconsistent,the blasting stress wave in the peripheral holes protecting surrounding rock mass is superimposed and enhanced in multiple parts,and is unevenly distributed along the tunnel excavation contour,resulting in overbreak in more parts,which is not conducive to the formation of a smooth and flat tunnel excavation profile.Therefore,in engineering practice,it is necessary to strictly control the external insertion angle.

关 键 词：铁道隧道 工程爆破 数值模拟 光面爆破 外插角 周边孔 岩石损伤 

分 类 号：U459.1[建筑科学—桥梁与隧道工程]