摘要
TBM隧道穿越微风化凝灰岩、节理密集带及断层破碎带时,极易诱发隧道内涌水,造成地下水位下降、水资源流失、地表塌陷等问题。本文基于泄水孔+深孔联合泄水设计,研究适用于高水压环境下的新型联合泄水式管片。在此基础上,基于等效衬砌法,利用有限元软件系统分析TBM隧道掘进过程中孔隙水压力、开挖面涌水量及地下水位在超前注浆与未注浆两种工况下的演化特征,并使用数据分析软件对隧道总涌水量和地下水位降深关系进行拟合。结果表明:隧道超前注浆造成孔压比随地质岩层渗透系数增大而降低,并使渗流场影响高度和宽度得到有效控制;超前注浆导致隧道在施工过程中开挖面拱顶孔压比基本保持在同一水平直线上,有效降低总涌水量上升速率;地下水位降深随隧道掘进距离增大而增大,且地下水位降深与掘进距离之间呈线性正相关。研究结果可为TBM隧道穿越不良地层诱发地下水环境负效应问题的处置提供技术支持。
When TBM tunnel passes through slightly weathered tuff,joint dense zone and fault fracture zone,it is easy to induce water gushing in the tunnel,resulting in groundwater level drop,water resources loss,surface collapse and so on.This paper is based on the joint drainage design of drainage holes+deep holes to study a new type of joint drainage segment suitable for high water pressure environments.In view of the above,based on the equivalent lining method,the finite element software system is used to analyze the evolution characteristics of pore water pressure,water inflow from excavation surface and groundwater level under advanced grouting and without grouting during the process of TBM tunnel excavation.The data analysis software is used to fit the relationship between the total water inflow of the tunnel and the lowering depth of the groundwater level.The results show that the pore pressure ratio caused by advance grouting in the tunnel decreases with the increase of the permeability coefficient of geological strata,and the influence height and width of seepage field are effectively controlled.Advance grouting makes the pore pressure ratio of the vault on the excavation surface of the tunnel basically keep at the same horizontal line during construction,effectively reducing the rising rate of total water inflow.The groundwater level drop depth increases with the increase of tunnel driving distance,and there is a linear positive correlation between groundwater level drop depth and tunneling distance.The research results can provide technical support for the treatment of the negative effects of groundwater environment induced by the actual construction of TBM tunnel through poor strata.
作者
宋勤
SONG Qin(China Railway 11th Bureau Group 4th Engineering Co.Ltd.,Wuhan Hubei 430061,China)
出处
《铁道建筑技术》
2024年第2期72-75,116,共5页
Railway Construction Technology
基金
中国国家铁路集团有限公司科技研究开发计划项目(K2018G014)
中铁十一局集团有限公司科技研究开发计划项目(19-AI-03)。
关键词
TBM隧道
地下水环境负效应
演化特征
等效衬砌
新型泄水管片
超前注浆
TBM tunnel
negative effect of groundwater environment
evolution characteristics
equivalent lining
new drainage segment
advance grouting
