ABSTRACT
In deep tunnel construction, rock joints can act as pathways for high-temperature groundwater inflow, resulting in safety hazards, construction delays, and increased project costs. To address these challenges, grouting using cement materials is widely employed as an important technique in tunnel engineering for reducing permeability and improving rock mass integrity. Successful grouting depends on the injectivity of the grout, which governs its ability to flow into rock fractures and reach the target distance. Injectivity is primarily controlled by the cementitious grout’s rheological properties, particularly viscosity, which are affected by various factors (e.g., cement type, water-cement ratio, elapsed time, and temperature). High temperatures significantly accelerate the time-dependent viscosity of cement grout, leading to increased clogging risk and reduced sealing efficiency. Therefore, evaluating the time-dependent viscosity characteristics of cement grouts under high temperature conditions is essential for predicting grout injection performance. This study focuses on evaluating the time-dependent viscosity effects on grout injection behavior in rock joints. This research is expected to provide a framework for understanding thermal effects on injection performance and provide practical insights for optimizing grouting strategies in complex geological conditions.
