非饱和地层中盾构隧道壁后注浆浆液渗透扩散机理  

Slurry Seepage and Diffusion Mechanism of Shield Tunnel Backfilling Grouting in Unsaturated Stratum

作　　者：杨琪[1,2] 耿萍[1,2] 唐睿 赵冰冰[1,2] 郭翔宇 何悦[1,2] YANG Qi;GENG Ping;TANG Rui;ZHAO Bingbing;GUO Xiangyu;HE Yue(School of Civil Engineering,Southwest Jiaotong University,Chengdu Sichuan 610031,China;Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu Sichuan 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610036 [2]西南交通大学交通隧道工程教育部重点实验室,四川成都610036

出　　处：《中国铁道科学》2020年第6期100-108,共9页China Railway Science

基　　金：国家自然科学基金资助项目(51878566,51578457);四川省重点研发项目(2018GZ0360,2020YFS0294);四川省科技计划项目(2019YFG0001)。

摘　　要：基于非饱和土理论,引入相关非饱和土渗透函数模型;结合盾构法施工的特点,研究非饱和地层中盾构隧道壁后注浆浆液的渗透扩散机理,得到非饱和地层中3种浆液渗透扩散模式时浆液扩散半径的计算公式,进而分析砂性地层中浆液扩散半径与注浆压力、注浆时间及浆液黏度时变性的关系。结果表明:浆液扩散半径随地层中土体的体积含水率增加而增大,且在地层处于气封闭状态时达到最大值;不考虑地层非饱和状态影响的浆液扩散半径计算结果偏大;随着注浆压力的增大,浆液扩散半径逐渐增大;地层处于气封闭状态和双敞开状态时,表示土体持水能力的非饱和特征参数α值越大,则浆液扩散半径越大,但受注浆压力增加的影响反而越小;地层处于水封闭状态时,基质吸力的变化对浆液扩散半径的影响不明显;浆液扩散半径随注浆时间的增加而逐渐增大,若不考虑浆液黏度时变性,其增加趋势更为明显。Based on the unsaturated soil theory, the slurry seepage and diffusion mechanism of shield tunnel backfilling grouting in unsaturated stratum was studied by introducing the permeability function model of unsaturated soil and combining with the characteristics of shield construction. The calculation formulas of slurry diffusion radius for three kinds of slurry seepage and diffusion modes in unsaturated stratum were obtained.Then, the relationship between the diffusion radius of slurry and grouting pressure, grouting time and the timevariation of slurry viscosity in sandy stratum was analyzed. Result show that the diffusion radius of slurry increases with the rise of the volumetric water content of the stratum and reaches the maximum value when the stratum is in gas sealing state. The calculation result of slurry diffusion radius is too large without considering the influence of the unsaturated state. With the rise of grouting pressure, the slurry diffusion radius gradually increases. When the stratum is in gas sealing state and double open state, the greater the unsaturated characteristic parameter α(water holding capacity of soil), the longer the slurry diffusion radius, but the smaller the effect caused by grouting pressure. When the stratum is in water sealing state, the effect of matrix suction variation on the diffusion radius of slurry is not obvious. The diffusion radius of slurry increases with the increase of grouting time, and the increasing trend is more obvious if the time-varying viscosity of slurry is not considered.

关 键 词：盾构隧道 壁后注浆 非饱和土理论 浆液扩散半径 体积含水率 

分 类 号：U451[建筑科学—桥梁与隧道工程]