Xie Bao, Cheng Hua, Wang Xuesong, Yao Zhishu, Rong Chuanxin, Zhou Ruihe, Zhang Liangliang, Guo Longhui, Yu Hong, Xiong Wei, Xiang Xusong
School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan 232001, China.
School of Resources and Environmental Engineering, Anhui University, Hefei 230601, China.
Materials (Basel). 2022 Nov 3;15(21):7763. doi: 10.3390/ma15217763.
In engineering, loose sandy (gravelly) strata are often filled with cement-based grout to form a mixed material with a certain strength and impermeability, so as to improve the mechanical properties of sandy (gravelly) strata. The tortuosity effect of sandy (gravelly) strata and the time-varying viscosity of slurry play a key role in penetration grouting projects. In order to better understand the influence of the above factors on the penetration and diffusion mechanism of power-law slurry, based on the capillary laminar flow model, this research obtained the seepage motion equation of power-law slurry, the time-varying constitutive equations of tortuosity and power-law fluid viscosity were introduced, and the spherical diffusion equation of penetration grouting considering both the tortuosity of porous media and time-varying slurry viscosity was established, which had already been verified by existing experiments. In addition, the time-varying factors of grouting pressure, the physical parameters of the injected soil layer, and slurry viscosity on penetration grouting diffusion law and the influencing factors were analyzed. The results show that considering the tortuosity of sandy (gravelly) strata and the time-varying of slurry viscosity at the same time, the error is smaller than the existing theoretical error, only 13~19%. The diffusion range of penetration grouting in the sandy (gravelly) strata is controlled by the tortuosity of sandy (gravelly) strata, the water-cement ratio of slurry, and grouting pressure. The tortuosity of sandy (gravelly) strata is inversely proportional to the diffusion radius of the slurry, and the water-cement ratio of slurry and grouting pressure are positively correlated with the diffusion radius. In sandy (gravelly) strata with a smaller particle size, the tortuosity effect of porous media dominates the slurry pressure attenuation. When the particle size is larger, the primary controlling factor of slurry pressure attenuation is the tortuosity effect of porous media in the initial stage and the time-varying viscosity of slurry in the later stage. The research results are of great significance to guide the penetration grouting of sandy (gravelly) strata.
在工程中，松散的砂质（砾质）地层常被注入水泥基浆液，形成具有一定强度和防渗性的混合材料，以改善砂质（砾质）地层的力学性能。砂质（砾质）地层的曲折效应和浆液的时变粘度在渗透灌浆工程中起着关键作用。为了更好地理解上述因素对幂律浆液渗透扩散机理的影响，基于毛细管层流模型，本研究得到了幂律浆液的渗流运动方程，引入了曲折度和幂律流体粘度的时变本构方程，建立了同时考虑多孔介质曲折度和浆液时变粘度的渗透灌浆球形扩散方程，该方程已得到现有实验的验证。此外，分析了灌浆压力的时变因素、被注入土层的物理参数以及浆液粘度对渗透灌浆扩散规律的影响因素。结果表明，同时考虑砂质（砾质）地层的曲折度和浆液粘度的时变，误差比现有理论误差小，仅为13%~19%。砂质（砾质）地层中渗透灌浆的扩散范围受砂质（砾质）地层的曲折度、浆液水灰比和灌浆压力控制。砂质（砾质）地层的曲折度与浆液扩散半径成反比，浆液水灰比和灌浆压力与扩散半径呈正相关。在粒径较小的砂质（砾质）地层中，多孔介质的曲折效应主导着浆液压力衰减。当粒径较大时，浆液压力衰减的主要控制因素在初始阶段是多孔介质的曲折效应，后期是浆液的时变粘度。研究结果对指导砂质（砾质）地层的渗透灌浆具有重要意义。
