摘要
分析了由于钢拱架限制周边眼开孔位置及外插角引起隧道超欠挖的原因,提出周边眼采用"长短眼"布孔的超欠挖控制爆破技术并阐述了其作用原理,并在青岛地铁延安路站车站主体Ⅰ部和Ⅳ部爆破开挖中实际应用。结果表明:周边眼采用"长短眼"布孔,"长短眼"炮孔间距同辅助眼,"短眼"爆破延期时间不小于"长眼","长短眼"单孔装药量按辅助眼计算方法,可使隧道基本无欠挖,最大超挖值控制在120mm以内,平均超挖值控制在60mm,隧道爆破成型良好。同时,周边眼爆破振速降低了12.5%。
The paper first analyzed the causes of overbreak and underbreak resulted from the hole position and external angle of periphery holes under the limitation of steel arch,and then put forward the control blasting technique of overbreak and underbreak by adopting＂long and short holes＂distribution in periphery holes and explained its principle.The technique was applied in the blasting excavation sites of main part I and IV of Qingdao Metro＇s Yan＇an Road Station.The results show that the ＂long and short holes＂technique in periphery hole distribution,with the same spacing as the spacing between the auxiliary holes,longer blasting delay time than that of＂long holes＂,and the single hole explosive load calculated in accordance with the single auxiliary hole explosive load,can ensure that no obvious outbreak takes place in tunnels and the maximum overbreak can be kept within 120 mm and the average overbreak within 60 mm,thus achieving good blasting molding.Meanwhile,this technique can reduce the blasting vibration velocity of the periphery holes by 12.5%.
出处
《山东科技大学学报（自然科学版）》
CAS
2016年第5期49-54,共6页
Journal of Shandong University of Science and Technology(Natural Science)
基金
国家自然科学基金项目(10672091)
2015-2016年度山东科技大学研究生科技创新基金项目(YC150304)
关键词
超欠挖
周边眼
布孔方式
钢拱架
分次起爆
overbreak and underbreak of tunnels
periphery hole
hole distribution
steel arch
stage initiation
