摘要
地下水环境对岩体结构有显著的弱化效应,因此富水软岩隧道面临极大的安全建造压力,研究其渗流-应力场在耦合影响因素下的演变机理对保障生态安全意义重大。结合固体力学与达西定律,采用流固耦合算法系统性地对富水软岩隧道渗流-应力场各影响因素进行研讨,具体讨论了不同施工阶段、渗透系数、注浆范围、围岩岩性下隧道地下水位、水压力等值线、外水压力的变化规律。研究可知:上台阶开挖后约4h水位基本稳定,降低了10.8m,开挖支护中台阶后,水位3h内继续降低了1.1m,下台阶开挖支护后水位仅下降了0.5m,并在1h后即保持稳定,施作二次衬砌后地下水位逐渐回涨,最终较初始水位仍低1.2m。渗透系数越小,地下水位越低,衬砌外水压力越小;不同注浆厚度对地下水位影响不明显,但注浆厚度越大,衬砌荷载与变形越小。
The groundwater environment has a significant weakening effect on the rock mass structure,so the water-rich soft rock tunnel faces great safety construction pressure.It is of great significance to study the evolution mechanism of the seepage-stress field under the coupling influence factors to ensure the ecological safety construction.Combined with solid mechanics and Darcy’s law,the influence factors of seepage-stress field of water-rich soft rock tunnel are systematically discussed by using fluid-solid coupling algorithm.The variation law of groundwater level,water pressure contour and external water pressure under different construction stages,permeability coefficient,grouting range and surrounding rock lithology is discussed in detail.The study shows that the water level is basically stable about 4 hours after the excavation of the upper step,which is reduced by 10.8m.After the excavation and support of the middle step,the water level continues to decrease by 1.1m within 3 hours.After the excavation and support of the lower step,the water level only decreases by 0.5m,and it remains stable after 1 hour.After the secondary lining is applied,the groundwater level gradually rises,and finally it is still 1.2m lower than the initial water level.The smaller the permeability coefficient,the lower the groundwater level and the smaller the external water pressure of the lining.The influence of different grouting thickness on groundwater level is not obvious,but the larger the grouting thickness,the smaller the lining load and deformation.
作者
徐大松
郝跃武
蒋长伟
XU Dasong;HAO Yuewu;JIANG Changwei(Sichuan Shugao Innovation Industry Co.,Ltd.,Chengdu,Sichuan 610031,China;Key Laboratory of Transportation Tunnel Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)
出处
《施工技术(中英文)》
2025年第10期50-55,63,共7页
Construction Technology
基金
四川省交通运输科技项目(2018-ZL-04)。
关键词
隧道
流固耦合
地下水位
渗透系数
外水压力
tunnels
fluid solid coupling
groundwater level
permeability coefficient
external water pressure
