摘要
四川甘孜硬梁包水电站引水隧洞开挖断面半径最大达7.82 m,采用超前小导管预支护下的多台阶分层开挖方法。采用FLAC3D数值分析软件对过沟浅埋段隧洞开挖变形进行了数值研究,研究结果表明在过沟浅埋段针对Ⅳ类围岩采用台阶法开挖,能很好的控制隧洞变形,并且能满足支护结构的安全性要求。分层开挖对隧洞变形有影响,在上层开挖时,主要影响拱顶沉降变形,在开挖中层时,拱顶沉降较小,隧洞变形主要存在于水平向,在后期进行中层开挖时,应注意水平收敛变形的监测,并保证中层锁脚锚杆的施工质量。
The headrace tunnel of Yingliangbao Hydropower Project in Ganzi Prefecture of Sichuan has a maximum excavation radius of 7.82 m,and the multi-step layered excavation method under the advanced small pipe pre-support is adopted.FLAC3D numerical analysis software is used to carry out numerical research on the excavation deformation of the tunnel in the shallow-buried section.It is shown that the deformation of the tunnel can be well controlled and meet the safety requirements of the support structure using step excavation method.The influence of layered excavation on the tunnel deformation mainly affects the downward deformation of the arch roof in the upper excavation.In the middle excavation,the deformation of the arch roof is small,and the tunnel deformation mainly exists in horizontal direction.In the later middle excavation,attention should be paid to the monitoring data of the horizontal convergence deformation,and the construction quality of the middle foot locking rock bolt should be ensured.
作者
陈涛
袁超义
薛瑞华
佟强
何本国
CHEN Tao;YUAN Chaoyi;XUE Ruihua;TONG Qiang;HE Benguo(Sichuan Huaneng Luding Hydropower Co.,Ltd.,Luding Sichuan 626100;Northeastern University,Shenyang Liaoning 110819)
出处
《四川水力发电》
2023年第1期93-96,104,共5页
Sichuan Hydropower
关键词
大断面
隧洞
施工
数值模拟
稳定性
Large section
Tunnel
Construction
Numerical simulation
Stability
