硅溶胶因渗透性和可注性好、耐久性强、无毒环保等特性在防渗注浆领域极具应用前景，但单一硅溶胶存在凝固可控性差的问题导致其实际应用受限。在硅溶胶中添加盐溶液/酸度调节剂及两者同时添加可调控其凝结固化行为，但目前关于盐溶液和酸度调节剂对硅溶胶组成结构、黏度和凝结时间等的影响及其机理尚不完全明确。基于此，选用氯化钙溶液和乙酸，将其分别或同时加入硅溶胶中，研究二者对硅溶胶组成结构、黏度、凝结时间等的影响并阐明其影响机理，同时考察硅溶胶/氯化钙/乙酸体系固砂体的强度和渗透系数等指标。结果表明：氯化钙可显著促进硅溶胶的凝结，硅溶胶的黏度在短时间内迅速上升；添加乙酸后，硅溶胶的黏度增长缓慢，凝结时间较长；而同时添加氯化钙和乙酸后，硅溶胶的黏度经历先缓慢增长，再迅速上升的过程，且通过控制氯化钙的浓度可有效调控硅溶胶的凝结时间。添加硅溶胶/氯化钙/乙酸体系后，硅溶胶固砂体的3 d抗压强度均大于0.39 MPa，固砂体的渗透系数可保持在数量级为1×10^-9 cm/s范围。研究结果可为硅溶胶注浆材料的制备及其在注浆领域的应用提供一定理论基础。

Silica sol has great application prospects in the field of anti-seepage grouting due to its good permeability and injectivity，strong durability，non-toxic and environmental protection.The practical application of single silica sol is limited due to its poor solidification controllability.Adding salt solution/acidity regulator and both can regulate the solidification behavior of silica sol.However，the influences of salt solution and acidity regulator on the composition，viscosity and setting time of silica sol and their mechanisms are still not completely clear.In this paper，calcium chloride solution and acetic acid were selected and added to silica sol respectively or simultaneously to study their effects on the composition，viscosity and setting time of silica sol and elucidate their effects mechanism.At the same time，the strength and permeability coefficient of silica sol/calcium chloride/acetic acid system were investigated.The results showed that calcium chloride could significantly promote the condensation of silica sol，and the viscosity of silica sol was increased rapidly in a short time.After the addition of acetic acid，the viscosity of silica sol was increased slowly and the setting time was longer.When calcium chloride and acetic acid were added at the same time，the viscosity of silica sol experienced a slow increase at first，and then a rapid rise，and the setting time of silica sol could be effectively controlled by controlling the concentration of calcium chloride.After the addition of silica sol/calcium chloride/acetic acid system，the 3 d compressive strength of silica sol solid sand body was greater than 0.39 MPa，and the permeability coefficient of silica sol solid sand body could be maintained in the range of 1×10^-9 cm/s.The results could provide a theoretical basis for the preparation of silica sol grouting materials and their application in the field of grouting.