Zhang Weijie, Yang Fei, Han Chenghao, Ren Qian, Peng Ziyu, Wu Fangxiao, Zhang Zhenyong
College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
Xi'an Research Institute of China Coal Technology & Engineering Group Corp, Xi'an 710054, China.
ACS Omega. 2021 Oct 13;6(42):28140-28149. doi: 10.1021/acsomega.1c04216. eCollection 2021 Oct 26.
Subject to the complex hydrogeological environment where underground engineering is located, the grouting prevention and control of microfissure water ingress are increasingly strict. Silica sol grout has been increasingly used in field tests because of its fine particles and good injectability. Therefore, it is necessary to examine the time-dependent viscosity of silica sol grout and clarify its diffusion law in a rock fissure. In this study, the time dependence of the viscosity of silica sol grout was studied, and then the grout viscosity was subdivided into a slow growth period, accelerated growth period, and rapid curing period according to the growth rate. The effects of the concentration of colloidal silica suspension, the concentration of accelerant, and the mixing volume ratio of the two on the growth of the slurry viscosity were studied. A parameter λ was introduced to comprehensively characterize the influence of the three factors on the rheological properties of the slurry. The relationship between the gel induction time and λ and the accelerating growth stage of the slurry gel was obtained by data fitting. The time-dependent equation of the silica sol solution was established. The difference in the grouting diffusion law between silica sol grout and cement-sodium silicate grout (C-S grout) is compared and analyzed by a stepwise calculation method under two grouting modes (constant-pressure grouting and constant-rate grouting). The results show that under the condition of constant-pressure grouting, the silica sol grout migrates and diffuses continuously for a long time, while the C-S grout is close to the final diffusion form at 15-20 s, and the maximum diffusion distance is much smaller than that of silica sol grout. Under the condition of constant-rate grouting, the grouting pressure driving C-S grout increases sharply with time. Compared with C-S grout, silica sol grout has the obvious advantages of a longer effective diffusion time and lower energy consumption. The research results have certain theoretical significance and reference value for the engineering design of silica sol grouting.
受地下工程所处复杂水文地质环境的影响，对微裂隙涌水的注浆防治要求日益严格。硅溶胶浆液因其颗粒细小、可注性好而在现场试验中得到越来越广泛的应用。因此，有必要研究硅溶胶浆液的时变黏度，并阐明其在岩石裂隙中的扩散规律。本研究对硅溶胶浆液黏度的时变性进行了研究，然后根据其增长速率将浆液黏度细分为缓慢增长期、加速增长期和快速固化期。研究了硅溶胶悬浮液浓度、促凝剂浓度以及二者的混合体积比对浆液黏度增长的影响。引入参数λ来综合表征这三个因素对浆液流变性能的影响。通过数据拟合得到了凝胶诱导时间与λ以及浆液凝胶加速增长阶段之间的关系。建立了硅溶胶溶液的时变方程。采用逐步计算法，对比分析了在两种注浆方式（恒压注浆和恒量注浆）下硅溶胶浆液与水泥-水玻璃浆液（C-S浆液）注浆扩散规律的差异。结果表明，在恒压注浆条件下，硅溶胶浆液长时间持续迁移扩散，而C-S浆液在15-20 s时接近最终扩散形态，最大扩散距离远小于硅溶胶浆液。在恒量注浆条件下，驱动C-S浆液的注浆压力随时间急剧增加。与C-S浆液相比，硅溶胶浆液具有有效扩散时间长、能耗低的明显优势。研究成果对硅溶胶注浆工程设计具有一定的理论意义和参考价值。
