摘要
为了防止盾构输水隧洞施工过程中因支护压力控制不当导致掌子面失稳,以韩江-榕江-练江水系连通后续优化工程为依托,采用FLAC3D软件建立三维数值模型。针对该盾构输水隧洞穿越的4种典型地层,模拟分析了不同支护压力条件下盾构施工过程中的掌子面稳定性,研究了各工况下掌子面及其前方塑性区的发展规律,并进一步确定了各地层掌子面的极限支护压力下限值。研究结果表明:1)淤泥质土、黏土、泥质中粗砂和泥质粉砂岩4种地层对支护压力变化的敏感度依次降低;2)当支护压力比逐渐减小时,塑性区向掌子面方向发展,且在掌子面失稳时,其前方会出现对数螺线型塑性区;3)对于淤泥质土、黏土和含泥质中粗砂3种地,其极限支护压力比及建议值分别为0.69(建议值为0.90)、0.57(建议值为0.80)、0.41(建议值为0.65)。而对于泥质粉砂岩地层,掌子面具有自稳能力,建议支护压力比为0.6。本文研究成果可为类似工程盾构施工提供参考。
In order to prevent the instability of the tunnel face due to improper support pressure control during the construction of the shield water transmission tunnel,a three-dimensional numerical model is established by FLAC”software based on the follow-up optimization project of the connection of the Hanjiang-Rongjiang-Lianjiang water system.Aiming at the four typical strata traversed by the shield water transmission tunnel,the stability of the tunnel face during shield construction under different support pressure conditions is simulated and analyzed,the development law of the tunnel face and its front plastic zone under various working conditions is studied,and the lower limit of the ultimate support pressure of the tunnel surface in various layers is further determined.The results show that:1)The sensitivity of four strata,namely silty soil,clay,argillaceous coarse sand and argillaceous siltstone,decreases in turn;2)When the support pressure ratio gradually decreases,the plastic zone develops towards the tunnel surface,and when the tunnel surface is unstable,a logarithmic spiral plastic zone will appear in front of it;3)For the three types of silty soil,clay and argillaceous coarse sand,the ultimate support pressure ratio and recommended values are 0.69(recommended value is 0.90),0.57(recommended value is 0.80)and 0.41(recommended value is 0.65),respectively.For argillaceous siltstone formations,the tunnel face has self-stabilizing ability,and the recommended support pressure ratio is 0.6.The results can provide reference for the construction of shield construction in similar projects.
作者
王良俊
庞瑞祺
李长青
任国卿
陈保国
WANG Liangjun;PANG Ruiqi;LI Changqing;REN Guoqing;CHEN Baoguo(Sinohydro Bureau 7Co.,Ltd.,Chengdu 610081,Sichuan,China;Engineering Faculty,China University of Geosciences,Wuhan 430074,Hubei,China)
出处
《工程建设》
2025年第8期48-54,63,共8页
Engineering Construction
关键词
盾构隧道
掌子面稳定性
塑性区
极限支护压力
数值模拟
shield tunnel
tunnel face stability
plastic zone
ultimate support pressure
numerical simulation
