It’s a universal engineering problem to seal micro-cracks of low-permeability argillaceous rock mass by grouting in the fields of civil engineering and mining. This paper achieved the grouting sealing of low- permeability artificial rocks with the permeability of 0.1–40 mD by adopting silica sol imbibition grouting. The variation characteristics of particle size, viscosity, and contact angle of silica sol during solidification and the pore size distribution of low-permeability artificial rocks were measured, and spontaneous imbibition tests of the artificial rocks were carried out. Finally, combined with the imbibition theory, percolation theory, and fracture medium grouting principle, the silica sol imbibition mechanism of low-permeability rocks and soil was discussed. The results show that: (1) Silica sol can be injected into artificial rocks with the minimum permeability of 0.1 mD through spontaneous imbibition; (2) The particle size increase of silica sol leads to decreased wettability, affinity, and injectability in grouting materials; and (3) In the range of 0.1–40 mD, the grout absorption first increases and then decreases with increased permeability. The number of large pores and fractures in the rock mass is related to injectability, and the number of small and medium pores is related to the internal driving force of imbibition. This study provides a theoretical basis for silica sol grouting sealing of low-permeability argillaceous rocks and is, therefore, an important reference for application.

灌浆封堵低渗透泥质岩体微裂缝是土木工程和采矿等领域普遍存在的工程问题。本文采用硅溶胶自吸注浆实现了渗透率为0.1～40 mD的低渗透人造岩的注浆封堵。测量了硅溶胶在凝固过程中的粒径、粘度和接触角的变化特征以及低渗透人造岩的孔径分布，并进行了人造岩的自吸试验。最后，结合自吸理论、渗流理论和裂缝介质注浆原理，探讨了低渗透岩土的硅溶胶自吸机理。结果表明：(1) 硅溶胶可以通过自吸作用注入到最小渗透率为0.1 mD的人造岩石中；(2)硅溶胶粒径增大导致灌浆材料的润湿性、亲合性和可注入性降低；(3) 在0.1～40 mD范围内，随着渗透率的增加，灌浆吸收量先增加后减少。岩体中大孔隙和裂缝的数量与可注入性有关，中小孔隙的数量与自吸的内驱力有关。该研究为低渗透泥质岩的硅溶胶注浆封堵提供了理论依据，具有重要的应用参考价值。(2)硅溶胶粒径增大导致灌浆材料的润湿性、亲合性和可注入性降低；(3) 在0.1～40 mD范围内，随着渗透率的增加，灌浆吸收量先增加后减少。岩体中大孔隙和裂缝的数量与可注入性有关，中小孔隙的数量与自吸的内驱力有关。该研究为低渗透泥质岩的硅溶胶注浆封堵提供了理论依据，具有重要的应用参考价值。(2)硅溶胶粒径增大导致灌浆材料的润湿性、亲合性和可注入性降低；(3) 在0.1～40 mD范围内，随着渗透率的增加，灌浆吸收量先增加后减少。岩体中大孔隙和裂缝的数量与可注入性有关，中小孔隙的数量与自吸的内驱力有关。该研究为低渗透泥质岩的硅溶胶注浆封堵提供了理论依据，具有重要的应用参考价值。岩体中大孔隙和裂缝的数量与可注入性有关，中小孔隙的数量与自吸的内驱力有关。该研究为低渗透泥质岩的硅溶胶注浆封堵提供了理论依据，具有重要的应用参考价值。岩体中大孔隙和裂缝的数量与可注入性有关，中小孔隙的数量与自吸的内驱力有关。该研究为低渗透泥质岩的硅溶胶注浆封堵提供了理论依据，具有重要的应用参考价值。