摘要
盾构隧道近接既有结构施工中常采用克泥效工法辅助控制地层位移。克泥效浆液的流变和渗透扩散性能对盾壳外环向间隙的填充效果具有重要影响。基于克泥效浆液X射线衍射试验(X-ray diffraction, XRD)和黏度试验,研究浆液微观成分及流变性能。基于多孔介质多相流控制方程,建立砂土中克泥效浆液扩散数值模型,分析浆液配比、地层渗透系数和注浆压力对扩散性能的影响。结合宾汉姆流体砂土渗流公式,验证数值模型的可靠性。结果表明:克泥效浆液成分主要为石英、斜长石、伊利石、正长石,且随A液水粉比增加,斜长石含量增加,伊利石含量减小。克泥效浆液的塑性黏度与屈服强度随A液水粉比的减小而增大,宾汉姆模型对浆液流变曲线的拟合优度大于0.95。克泥效浆液在环向间隙中的填充扩散阶段约为25s,而后再向地层中发生渗透扩散,渗透扩散速度远小于填充扩散。随A液水粉比、地层渗透系数、注浆压力增加,克泥效在地层渗透距离均会增加。
In the construction of shield tunnels close to existing structures,the clay shock method is often introduced to assist in the control of ground displacement.The rheological and penetration diffusion properties of clay shock slurry have an important influence on the filling effect of the circumferential gap outside the shield shell.Based on the X-ray diffraction(XRD)test and viscosity test of clay shock slurry,the microscopic composition and rheological properties of the slurry were investigated.Based on the control equations of multiphase flow in porous media,a numerical model of diffusion of clay shock slurry in sandy soil was established,and the effects of water-powder ratio,formation permeability coefficient and grouting pressure on the diffusion performance were analyzed.The reliability of the numerical model was verified by combining with the seepage equation of Bingham fluid in sandy soil.The results show that the composition of the clay shock slurry is mainly quartz,albite,illite and feldspar.With the increase of the water-powder ratio of liquid A,the albite increases and illite content decreases.The plastic viscosity and yield strength of the clay shock slurry increase with the decrease in the water-powder ratio of fluid A.The coefficient of determination of Bingham's model for the rheological curve of the slurry is more than 0.95.The filling-diffusion stage of the clay shock slurry in the circumferential gap is about 25 s,and then the penetration-diffusion into the formation occurs.The penetration-diffusion rate is much smaller than the filling-diffusion.With the increase of the water-powder ratio of liquid A,the permeability coefficient of the formation and the grouting pressure,the clay shock slurry in the formation penetration distance will increase.
作者
陈豪
张康健
史勇
陈勇
张志强
CHEN Hao;ZHANG Kang-jian;SHI Yong;CHEN Yong;ZHANG Zhi-qiang(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Chongqing Communications Construction(Group)Co.,Ltd.,Chongqing 400010,China)
出处
《科学技术与工程》
北大核心
2024年第16期6916-6926,共11页
Science Technology and Engineering
基金
国家自然科学基金高铁联合基金(U1934213)。
