摘要
为系统研究深埋千枚岩隧道变形规律及合理预留变形量,以银百高速安康至岚皋段3座典型千枚岩隧道群为工程依托,采用精密水准仪和收敛计对隧道全程拱顶下沉和水平收敛进行了长期跟踪监测,并结合实测数据建立相应的变形分析预测模型。结果表明:千枚岩隧道围岩变形总体较大且离散性高,拱顶下沉和水平收敛分别可达95.3 cm和90.1 cm,不同风化程度的千枚岩变形稳定时间为30~120 d;千枚岩隧道变形时程曲线采用指数函数拟合效果较好,拟合优度均在0.93以上且预测变形值与实测稳定值相对误差不超过15%;深埋千枚岩隧道采用三台阶七步开挖法施工时,微风化、中风化、强风化以及断层破碎带预留变形量建议取值依次为20~30 cm、30~45 cm、40~60 cm和55~80 cm。
In order to systematically study the deformation law and reasonable reserved deformation space for deep buried phyllite tunnel,the long-term tracking monitoring for arch crown subsidence and horizontal convergence in the whole course of tunnels were carried out using precision level and convergence meter,based on three typical phyllite tunnels in Ankang to Langao section of Yinbai expressway.The corresponding deformation analysis and prediction model were established combined with the measured data.The results show that the surrounding rock deformation of phyllite tunnels are large and highly discrete,the vault subsidence and horizontal convergence can reach 95.3 cm and 90.1 cm respectively.The deformation stability time of phyllite with different weathering degrees ranges from 30 to 120 d.The deformation time history curve of phyllite tunnel is fitted by exponential function,the goodness of which is more than 0.93,and the relative error between the predicted deformation value and the measured stability value shall not exceed 15%.When the deep phyllite tunnel is constructed by the Three-bench Seven-step excavation method,the recommended values of the reserved deformation of the tunnel in the slightly weathered,moderately weathered,strongly weathered and fault fracture zone are 20~30 cm,30~45 cm,40~60 cm and 55~80 cm.
作者
王恩波
昝文博
唐琨杰
周云鹏
WANG Enbo;ZAN Wenbo;TANG Kunjie;ZHOU Yunpeng(School of Civil Engineering,Shaanxi Polytechnic Institute,Xianyang 712000,China;School of Highway,Chang'an University,Xi'an 710064,China;An-lan Management Office of Shaanxi Communications Holding Group Co.,Ltd.,Xi'an 710000,China)
出处
《甘肃科学学报》
2022年第3期93-98,118,共7页
Journal of Gansu Sciences
基金
陕西省教育厅科技项目(21JK0502)。
关键词
深埋隧道
千枚岩地层
现场测试
变形规律
预留变形量
Deep-buried tunnel
Phyllite stratum
Field test
Deformation law
Reserved deformation space
