## 6 Engineering Applications  
### Curtain Grouting Design  
The air shaft at the \(-\)380 m level of the Zhongjiu Iron Mine, known as 2#, has a straight wall three-center arch section design for the vein lane. The roadway has a net width of 4.0 m, a net height of 3.7 m, and a net section of 14.1 m\({}^{2}\). To ensure the smooth passage of the roadway through the ore-rock contact zone, exploration and grouting for flyover curtain water are being carried out in the 2# vein lane. The exploration and injection will take place between the 46.8 m and 76.8 m points along the vein lane. The depth of exploration and injection will be 30 m. Water exploration work will be conducted on the surface at the 46.8 m position along the vein lane. The water exploration hole is positioned 500 mm inward from the contour line of the net diameter. The hole has a diameter of \(\Phi\)76 mm and  
Figure 16: Optimization calculation model of grouting hole spacing. (**a**) Original fabric hole design; (**b**) Optimized rear fabric hole design.  
Figure 17: The grout diffusion pattern changes after hole optimization. (**a**) First sequence hole grouting; (**b**) Second sequence hole grouting; (**c**) Third sequence hole grouting.  
a depth of 30 m. The orifice pipe is made from \(\Phi\)95 \(\times\) 5 mm \(\times\) 6000 mm seamless steel pipe. There are a total of 10 holes, with 7#, 5#, and 6# being the first sequence, 1#, 2#, and 3# being the second sequence, and 4# and 8# being the third sequence. The 9# and 10# holes are designated as inspection holes. The diagram illustrating the arrangement can be observed in Figure 18, with the measurements in millimeters.  
A flow chart of the grouting process is shown in Figure 19. The primary components consist of three aspects:  
1. The task involves transporting materials and mixing slurry, specifically cement, water glass, and water, in accordance with a prescribed water-cement ratio to create a cement-water glass slurry. The objective is to prevent blockages and pipe clogs during the grouting process.
2. The grouting pump should be controlled based on the real grouting conditions, and the pump should be promptly started and stopped as needed. It is important to continuously monitor the grouting pressure to prevent pipe blockage and pipe collapse.
3. When connecting the orifice pipeline, it is important to carefully monitor the grouting situation on the working surface. It is necessary to promptly identify any leaks, pipe blockages, or other accidents and effectively control the grouting volume and pressure. Additionally, grouting valves should be promptly removed and cleaned as needed.  
The material used is a quick-setting slurry made by mixing cement and water glass. The cement used is ordinary silicate cement of grade 42.5. The water-cement ratio is controlled between 0.4 and 0.6. A high-efficiency water-reducing agent is added to the cement in an amount of 0.7 to 1.0%. The water glass slurry has a concentration of 10 to  
Figure 18: Schematic layout of grouting holes in the 2# vein-piercing lane at the \(-\)380 m level of the wind shaft of Zhongjiu Iron Mine. (**a**) Schematic layout of grouting holes; (**b**) The construction of the grouting hole; (**c**) Side view of grouting hole layout.  
12\({}^{\circ}\)Be. The ratio of cement slurry to water glass slurry is 1:1. The speed of the slurry is 0.5 m/s.