Research on the Performance of Cement-Sodium Silicate Grout for Synchronous Grouting in Shield Tunnel

Compared to single-fluid grout, cement-sodium silicate grout have the characteristics of shorter gel time and faster early strength. Based on filling the annular void at the shield tail, they can effectively prevent the flotation of segments. Therefore, it is necessary to analyze the performance of cement-sodium silicate grout and determine the optimal ratio for construction. To investigate the grout performance under different water-cement ratios and the volume ratio of liquid A to liquid B, this paper designed indoor grout experiments with different grout ratios and tested the gel time, initial setting time, final setting time, and compressive strength of the grout. The main conclusions are as follows: the gel time of the grout is positively correlated with the water-cement ratio and negatively correlated with the volume ratio of the grout; the initial setting time and final setting time of the grout are positively correlated with the water-cement ratio and the volume ratio of the grout; the strength of the grout is negatively correlated with the water-cement ratio and the volume ratio of the grout. Furthermore, by conducting function fitting for the gel time, initial setting time, final setting time, and compressive strength of the grout under different water-cement ratios and grout volume ratios, this study provides a basis for selecting ratios for subsequent projects using cement-sodium silicate grout and offers scientific guidance for grout adjustment during tunnel construction.