摘要
隧道洞内爆破容易诱发洞口边坡,尤其是松散堆积体失稳,开展爆破荷载作用下边坡稳定性分析方法研究,对于完善隧道进洞施工方法和设计理论具有重要意义。将隧道洞内爆破荷载等效为波动应力函数,基于传递系数法原理,建立了隧道爆破开挖作用下的洞口边坡稳定性计算方法,基于渝湘高速樵坪山隧道开展了应用研究。结果表明:(1)在隧道开挖爆破荷载作用下,洞口堆积层边坡的动力稳定系数随时间呈现衰减型正弦波动变化,约10ms时达到最小值,0.2s后趋于静力稳定系数;(2)在隧道距堆积层边坡的距离等于隧道跨度径距,且边坡倾角为25°的条件下,安全的最大单段炸药量为6.5kg;(3)堆积层边坡倾角越大,在爆破开挖过程中边坡动力稳定系数变化幅度越低;(4)堆积层厚度越小,边坡在动力扰动下越容易失稳,当堆积层厚度不超过2.5 m时,边坡在爆破过程中出现动力失稳。
The blasting in the tunnel is easy to induce the instability of the slope at the entrance,especially the loose accumulation body.It is of great significance to study the analysis method of slope stability under blasting load for improving the construction method and design theory of tunnel entrance.Taking blasting load in the tunnel equivalent to the wave stress function,and based on the principle of the transfer coefficient method,the calculation method of the stability of the tunnel slope under the action of tunnel blasting excavation was established,and based on Qiaopingshan Tunnel of Yuxiang Expressway,the application research was carried out.The results show that under the blasting load of tunnel excavation,the dynamic stability coefficient of the accumulation slope at the tunnel entrance presents an attenuation sine wave change with time,reaches the minimum value at about 10ms,and tends to the static stability coefficient after 0.2s.Under the condition that the distance between the tunnel and the accumulation slope is equal to the span diameter of the tunnel and the slope angle is 25°,the maximum safe explosive amount per section is 6.5kg.The larger the slope angle of the accumulation slope,the lower the variation range of the dynamic stability coefficient of the slope during the blasting excavation process.The smaller the thickness of the accumulation is,the easier the slope is to lose stability under dynamic disturbance.When the thickness of the accumulation does not exceed 2.5m,the slope will lose stability during blasting.
作者
黄锋
江鹏飞
李思远
杨永浩
张庆明
HUANG Feng;JIANG Pengfei;LI Siyuan;YANG Yonghao;ZHANG Qingming(State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Chongqing Communications Construction(Group)Co.,Ltd.,Chongqing 401122,China)
出处
《矿业研究与开发》
CAS
北大核心
2024年第1期67-72,共6页
Mining Research and Development
基金
重庆市自然科学基金面上项目(cstc2020jcyj-msxmX0679)
国家自然科学基金面上项目(52078090)
省部共建山区桥梁及隧道工程国家重点实验室开放基金项目(SKLBT-19-006,SKLBT-YF2106)
重庆市研究生联合培养基地项目(JDLHPYJD2020018).
关键词
隧道
堆积层边坡
爆破开挖
动力稳定性
传递系数法
Tunnel
Accumulation slope
Blasting excavation
Dynamic stability
Transfer coefficient method
