摘要
为研究爆破开挖时砾岩路堑边坡的动力响应特性,以渑淅高速公路路堑爆破开挖工程为依托,在现场监测基础上,结合数值模拟对爆破破岩过程进行了研究。研究结果表明:路基深孔爆破产生的振动速度场、应力场和位移场在边坡坡形变化处产生明显波动,且随爆心距的增加呈现衰减趋势,但衰减速率在逐渐减小;沿边坡坡形变化的不同高程处,垂向和径向质点峰值振速存在高程放大效应;最大主应力在允许范围内,台阶坡脚处不会因为应力集中而造成边坡岩体破坏;以砾岩动抗拉强度作为边坡失稳的极限状态,路堑边坡岩体爆破开挖质点振速安全阈值为24.62 cm/s,后续路基爆破开挖可通过实时监测进行安全控制。
In order to study the dynamic response characteristics of conglomerate cutting slope during blasting excavation,the blasting excavation project of the cutting in the Zhejiang Expressway is taken as an example to study the blasting by field monitoring and numerical simulation.The results show that the vibration velocity field,stress field and displacement field produced by deep-hole blasting of subgrade fluctuated obviously at the side slope shape,and show a decreasing trend with the increase of blast center distance.The attenuation rates decrease gradually;The peak vibration velocity of vertical and radial particles have elevation amplification effect at different elevations of slope shape variation along the edge slope;The maximum principal stress is within the allowable range.The rock mass of slope will not be damaged by stress concentration at the foot of step slope.The dynamic tensile strength of conglomerate is taken as the limit state of slope instability.The safety threshold of particle vibration velocity of rock blasting excavation in cutting slope is 24.62 cm/s.The subsequent subgrade blasting excavation can be safely controlled by real-time monitoring.
作者
刘钊臣
刘佳杰
张小军
刘晓飞
高文学
Liu Zhaochen;Liu Jiajie;Zhang Xiaojun;Liu Xiaofei;Gao Wenxue(Beijing University of Technology,Beijing 100124,China;Beijing Municipal Road and Bridge Co.,Ltd.,Beijing 100045,China)
出处
《市政技术》
2023年第9期145-151,共7页
Journal of Municipal Technology
基金
爆破工程湖北省重点实验室开放基金(BL2021-23)。
关键词
路堑开挖
深孔爆破
鞭梢效应
高程放大
安全阈值
cutting excavation
deep hole blasting
whipping effect
elevation amplification
safety threshold
