异形孔水包爆破围岩粉碎范围研究  

Research on the crushing range of surrounding rock in special-shaped hole water bag blasting

作　　者：张学富[1,2] 李宁杰 周杰[1,2] 韩风雷[1,2] 张建 ZHANG Xuefu;LI Ningjie;ZHOU Jie;HAN Fenglei;ZHANG Jian(State Key Laboratory of Bridge and Tunnel Engineering in Mountainous Area,Chongqing Jiaotong University,Chongqing 400074,China;Faculty of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]重庆交通大学山区桥梁及隧道工程国家重点实验室,重庆400074 [2]重庆交通大学土木工程学院,重庆400074 [3]中国地质大学工程学院,武汉430074

出　　处：《振动与冲击》2023年第11期131-138,共8页Journal of Vibration and Shock

基　　金：国家重点研发计划子课题(2021YFB2600103-01);在渝高校与中科院所属院合作(HZ2021009);国家自然科学基金青年(41801053)。

摘　　要：隧道掘进中光面爆破的超欠挖、开挖轮廓线不光滑及爆破效率低是施工中最为关心的问题。针对异形孔水包爆破破岩机理的问题,基于岩石爆破损伤分区理论,拟合并推导出异形孔水包爆破的孔壁冲击力计算式及围岩粉碎区的计算式P_(d)=3028.4K_(d)^(-1.021)及围岩粉碎区的计算式R_(c)=(P/N[P_(r)])^(1/α)(r_(b)+l)。以重庆市黔江区正阳镇隧道为依托,以自制钻头为工具,通过异形孔水包爆破与常规爆破的对比试验以及岩石爆破损伤阈值的数值模拟,验证了计算式的可靠性。结果表明:前者公式拟合精度为R^(2)=0.996,后者围岩粉碎范围的理论值与实测值吻合;该爆破方式即使在复杂岩石节理中也能产生光滑的隧道开挖轮廓线;炸药径向不耦合系数K_(d)≤1.5内,炸药量的增加对围岩粉碎区的影响甚少,其主要对破裂区产生影响。In tunnel driving,the over-under-excavated values of smooth blasting,the uneven contour of excavation and low blasting efficiency are the most concerned problems in construction.Aiming at the problem of rock breaking mechanism by special-shaped hole water bag blasting,based on the theory of blasting.T,the calculation formula P_(d)=3028.4 K_(d)^(-1.021) of hole wall impact force of special-shaped hole water bag blasting is was fitted,and the calculation formula R_(c)=(P/N[P_(r)])^(1/α)(r_(b)+l)of surrounding rock crushing area is was derived.Based on the tunnel in Zhengyang Town,Qianjiang District,Chongqing,and with the self-made drill bit as the tool,the reliability of the calculation formula is was verified through the comparative experiment of special-shaped hole water bag blasting and conventional blasting and the numerical simulation of rock blasting damage threshold.The results show that the fitting accuracy of hole wall impact force formula is R^(2)=0.996,the theoretical value of surrounding rock crushing range formula is consistent with the measured value.This blasting method generates a smooth tunnel excavation profile even in complex rock joints,Radial radial decoupling coefficient K d of explosive,and the increase of explosive content in≤1.5 has little effect on the crushed area of surrounding rock when K_(d)≤1.5,which mainly affects the fracture area.

关 键 词：隧道爆破 异形孔 水包 粉碎区 

分 类 号：U455.6[建筑科学—桥梁与隧道工程]