摘要
研究目的:含水上第三系粉质黏土隧道在施工过程中常出现初期支护变形、开裂甚至整体塌方问题,一直困扰着隧道建设。本文依托晋中南铁路通道工程某隧道典型实例,结合现场调查、隧道监控量测,探讨含水上第三系粉质黏土隧道的变形特点,研究其支护措施方案,为同类围岩条件下的隧道建设设计提供理论及实践依据。研究结论:(1)上第三系粉质黏土隧道两侧边墙变形是拱顶沉降变形的1.5~2.0倍,且两侧边墙变形的稳定时间较长;(2)上第三系粉质黏土隧道的变形时空效应明显,时间上具有一定的滞后性,空间上往往发生大变形问题的位置不在掌子面,而在掌子面后方15~25 m的位置,即侧墙变形空间效应影响范围为3D^5D(D为开挖洞径);(3)隧道开挖后,采用强初期支护措施,有利于抵消含水上第三系粉质黏土围岩变形的时空效应,在未施作二次衬砌前,提供足够的抗力以抵消围岩的变形;(4)该研究结论可应用于同类土质隧道的设计和施工中。
Research purposes： There usually are many problems during tunnel construction in the Upper Tertiary water - rich clay tunnel, such as initial support deformation, cracking, even collapse. Based on a tunnel typical instance in Shanxi Central -south Region Railway corridor project, combined with field investigation and monitoring measurement, this paper discussed the deformation characteristics and analyzed the suitable support measures in the Upper Tertiary water- rich clay tunnel, and the research results can provide some scientific theory and construction guidelines. Research conclusions： （ 1 ） The convergence deformation of sidewalls is 1.5 ~ 2 times as much as that of the arch, and the stability of surrounding rock in deformation of sidewalls takes much more days in the Upper Tertiary water - rich clay tunnel. （2） The deformation of this clay tunnel is influenced by the combined time - spatial effects, and the ratio of deformation produced by the time - effect has hysteretic nature, the big deformation place don l often happened in the tunnel face, but in the back of 15 -25 m away from the tunnel face, just to say the sidewalls deformation effect range is 3 D - 5 D （ ＂D＂ means the diameter of tunnel excavating）. （3） After excavating the tunnel, using strong initial supports which can offset the effects of time - spatial characteristics, and also can provide enough resistance to offset the surrounding rock deformation before secondary lining construction. （4） The research results can be used widely into design and construction in the same geotechnical clay tunnel.
出处
《铁道工程学报》
EI
北大核心
2015年第6期40-44,共5页
Journal of Railway Engineering Society
关键词
土质隧道
变形特点
支护措施
铁路工程
clay tunnel
deformation characteristic
support measure
railway project
