Comparative experimental study on grouting of fine cement and ordinary cement in underground engineering

Underground projects such as water-sealed caverns, gas storages, and diversion tunnels have strict requirements for the control of regional seepage fields. Grouting is an important way to control the seepage field in the engineering area. The groutability under different geological conditions is different, and the sensitivity to the particle size of grouting material is different. It is necessary to carry out relevant experimental demonstrations to provide a scientific basis for engineering construction. Based on the grouting construction of a water-sealed cavern, and by conducting comparative experiments of ultra-fine cement, wet grinding fine cement, and ordinary cement grouting, the applicability of different types of grouting materials was studied in the project. The test results show that when the rock permeability is high, there is no obvious difference in the seepage control effect of the three grouting materials. Under the condition of the same permeability of rock mass, different materials were used for grouting, and the unit ash consumption was generally the same. With the increase in grouting pressure, the unit ash consumption of the grouting hole increased significantly, and the effect of grouting was significantly improved. When the rock permeability is very low, using ultra-fine cement or wet-grinding fine cement can further reduce the seepage of the surrounding rock. Therefore, there is no need to use ultra-fine cement and wet grinding fine cement for grouting on a large scale in this project. In special cases where the groutability of ordinary cement is not good, it is recommended to use ultra-fine cement and wet-ground fine cement and to reasonably adjust the grouting pressure to significantly improve the grouting effect.