摘要
千枚岩隧道具有明显的变形量大、变形时间长、支护难度大等特点,一直是交通建设中的重要难题之一。以米亚罗3号隧道为工程背景,通过现场勘测分析得出千枚岩隧道变形与破坏机理,并确定了隧道初期支护大变形长短注浆锚杆联合支护方法,及在隧道开挖后第42 d为时间点作为隧道二次衬砌施作的选择。现场实践表明,采用确定的围岩大变形控制方案后,隧道拱顶沉降和水平收敛分别稳定在159.6 mm和127.4 mm,且二次衬砌产生的围岩应力非常小且分布均匀,说明采用初期支护大变形控制技术后,隧道初期支护具有较强的支护能力,能有效降低隧道的二次衬砌压力,对二次衬砌的长期使用起着至关重要的作用。研究成果可为千枚岩隧道大变形控制及施工提供技术指导。
Phyllite tunnel has obvious characteristics of large deformation,long deformation time,and difficult support,which has been one of the important problems in transport construction.This paper took Miyaro No.3 Tunnel as the engineering background,analyzed the deformation and damage mechanism of the tunnel through on⁃site investigation,and determined the joint support method of long and short grouting anchors for large deformation of the tunnel initial support,and the 42nd day after tunnel excavation as the choice of the secondary lining of the tunnel.Field practice shows that,after adopting the determined control programme for large deformation of surrounding rock,the tunnel vault settlement and horizontal convergence are stable at 159.6 mm and 127.4 mm respectively,and the surrounding rock stress generated by the secondary lining is very small and uniformly distributed,which indicates that,after adopting the initial support large deformation control technology,the tunnel initial support has a strong supporting capacity,which can effectively reduce the secondary lining pressure of the tunnel and play a vital role in the long⁃term use of the secondary lining.The results of the study can provide technical guidance for the control of large deformation and construction of tunnels in phyllite.
作者
王洪坤
WANG Hongkun(China Railway 20th Bureau Group Co.Ltd.,Xi′an Shaanxi 710016,China)
出处
《铁道建筑技术》
2024年第7期136-139,共4页
Railway Construction Technology
基金
中铁二十局集团有限公司科研计划课题(YF1903QL04B)。
关键词
千枚岩隧道
施作时机
长短注浆锚杆
二次衬砌
大变形控制
phyllite tunnel
timing of application
long and short grouting anchors
secondary lining
large deformation control
