## 5 Scheme and Application of Grouting Reinforcement Support
### Analysis of Roadway Surface Displacement Monitoring Results and Support Evaluation  
(1) Layout of monitoring points  
As shown in Figure 11, six displacement monitoring points are designed in the grouting section and the non-grouting section, which are ABCDEF in turn, with a distance of 35 m between points. The section of the grouting reinforcement support scheme is 100 m long, including DEF points, and ABC points are arranged in 100 m of the original support scheme section for a total of 200 m in the test section. The specific arrangement is shown in Figure 11. The \"cross\" point distribution method is adopted to measure the displacement and deformation of the roadway, and the measurement is conducted every other day. (2) Analysis of displacement monitoring results  
Figure 12 shows the width and displacement change curve of both sides of the mining roadway on the ZF3806 working face. During the monitoring period, the two sides of the ABC point in the non-grouting section moved inward obviously, the displacement changed significantly, and the displacement changed in a curve. At the initial stage, the  
Figure 11: Layout of monitoring points. Figure 10: Roadway support scheme. distance between the two sides of DEF points in the grouting section has a noticeable displacement change, and the changing trend of the three points is roughly the same, showing a small amount of deformation at first and then tending to be stable. At the same time, sudden inward movement on two sides occurred at six monitoring points. The maximum displacement of the non-grouting section is 0.42 m, and the maximum displacement of the grouting section is 0.2 m. According to the analysis of its causes, in the initial monitoring stage, the mining face is far away from the monitoring point, resulting in an insignificant mining impact; thus, the displacement change of the two sides of the roadway is small. When the mining face continues to advance, the monitoring point enters the mining influence range, causing large deformations on both sides of the non-grouting section roadway. In comparison, the deformation of the two sides of the grouted roadway section is small. The layered grout reinforcement and support can strengthen the stability of the two sides. Only under the influence of periodic pressure, the two sides of the grouting section and the non-grouting section have noticeable displacement changes. Figure 13 shows the curve of distance change and displacement change of the roof and floor of the mining roadway on the ZF3806 working face. The changing trend of the top and bottom plate distance at the ABC point of the non-grouting section is the same with large deformation and damage. The closer the roadway is to the working face, the faster the roof will cause subsidence, and with the advancement of the working face, the subsidence speed will accelerate significantly. Three DEF points in the grouting section have a small deformation at the initial stage, which is gradually stable later. The deformation is small, and the overall deformation only occurs near the working face. The deformation difference between the non-grouting section and the grouting section is noticeable. The maximum deformation of the non-grouting section can reach more than 0.53 m, and the maximum deformation of the grouting section is about 0.12 m. After grouting, the roof deformation of the grouted section is small, there is no bolt falling off or roof caving, and the roadway integrity is good. The analysis shows the roof crack in the non-grouting section is developed and has a high degree of fragmentation, which is easily affected by mining. There is obvious deformation and damage during periodic weighting. After grouting, the roof of the grouting section formed an integral structure with good integrity. At the initial stage, because the grouting fluid has not reached its stable strength, the roof has a small amount of displacement, and at the later stage, there is a small amount of overall subsidence under the influence of mining.