摘要
大断面隧道爆破,单次循环装药量大,对隧道围岩的稳定性影响显著。以赣-深高铁龙南隧道1#斜井大断面隧道为工程背景,借助数值模拟与现场测试方法,揭示了隧道开挖爆破作用下的围岩的振动响应特征,基于此特征进一步研究隧道爆破作用下不同位置沿开挖轴线方向损伤范围的分布,并提出围岩爆破振动速度控制值。研究表明:不同开挖断面,各方向峰值振动速度最大值出现的位置均不相同,剪应力最大值与拉应力最大值出现的位置不一致;隧道爆破作用下,底板中部爆破振动速度衰减最快,围岩损伤范围最大。拱肩与拱顶位置衰减最慢,围岩损伤范围最小。本次爆破条件下,隧道围岩最大损伤深度为4.0 m,距掌子面34 m开挖断面处围岩爆破振动控制值为5.83 cm/s。
Blasting excavation of large-section tunnel,with a large charge in a single cycle,has an significant influence on the stability of the surrounding rock of the tunnel.Based on the engineering background of the No.1 inclined shaft large section tunnel of Longnan tunnel of Ganzhou—Shenzhen high-speed rail,numerical simulation and field monitoring were adopted to reveal the vibration response characteristics of the surrounding rock under blasting excavation.Based on the characteristics,the damage distribution of different positions along the excavation axis under the tunnel blasting excavation was further studied.The control value of blasting vibration velocity of the surrounding rock was proposed.The results show that in different excavation sections,the positions of the maximum peak particle vibration velocity in each direction are different and the location of the maximum shear stress is inconsistent with that of the maximum stress.The maximum damage scale of surrounding rock appears in the middle of the floor where the largest attenuating rate of peak particle velocity occurs and the minimum appears in the arch and the vault where the smallest attenuating rate of peak particle velocity occurs.The maximum damage depth of the surrounding rock is 4.0 m and the critical vibration velocity is 5.83 cm/s under this blasting condition.
作者
吉凌
周传波
张波
王凤喜
JI Ling;ZHOU Chuanbo;ZHANG Bo;WANG Fengxi(Faculty of Engineering,China University of Geosciences,Wuhan 430074,China;The 3th Construction Company Ltd.of China 16th Corporation,Huzhou 313000,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2021年第7期161-168,共8页
Journal of the China Railway Society
基金
国家自然科学基金(41972286)
青年科学基金(41807265)。
关键词
隧道
爆破
峰值振动速度
最大拉应力
损伤范围
tunnel
blasting
peak vibration velocity
the maximum tensile
damage scale
