## 4 Results and Discussion  
### Establishment and Application of Evaluation Models  
#### 4.1.1 Determination of the Weights of Indicators  
During the grouting process, a certain amount of pressure must be applied to overcome various resistance factors such as static water pressure, allowing the grout to penetrate into the rock layers in order to meet the design requirements for grout diffusion [47]. Grouting pressure is the main controlling factor in grouting construction, which directly affects grouting diffusion, crack filling, and grouting effectiveness. The permeability coefficient characterizes the permeability of fluids to rock and soil, and can reflect the permeability level of rock layers after grouting. During the grouting process, the leakage of drilling fluid can also quantitatively evaluate the effectiveness of grouting to a certain extent. It can reveal the geological structure of the coal seam floor within the influence range of the hole. Drills with high leakage have complex geological structures and well-developed faults or dense karst fractures in the overlying strata; The geological structure of the drilling coverage area with less leakage is relatively simple. The complexity of the geological structure will affect the subsequent grouting project. The more complex the geological structure, the higher the requirements for grouting technology and the greater the construction difficulty [48]. Therefore, it will have a certain impact on the grouting effect. Unit grouting volume refers to the average amount of cement consumed per meter in the injection hole section, which can objectively reflect the development of fractures. The more uniform the unit groutingvolume data, the more uniform the development of formation fractures. Conversely, the more significant the spatial differences in the development of formation fractures. The combination of the CRITIC and PC methods is employed to determine the indicator weights. In the PC method, the first step is to construct the PC weight table, as illustrated in Table 1. The average value for each analysis item is calculated, followed by a pairwise comparison based on these averages. If an item's average value is larger, it is assigned 1 point; if smaller, it receives 0 points; and if the averages are equal, 0.5 points are assigned. A higher average value signifies greater importance, resulting in higher corresponding weights. Once the PC weight calculation table is completed, the TTL value is calculated to obtain the final weight. First, the weight calculation table from the precedence diagram is used to sum the values for each row, yielding the TTL value. This TTL value is then normalized, resulting in the final weight values (Table 2). CRITIC weights are calculated based on the variability of evaluation indicators and the degree of conflict between them. Variability is assessed using standard deviation, with higher deviations corresponding to greater weights. Conflict is gauged by the correlation coefficient between indicators; stronger correlations indicate lower conflict and, therefore, lower weights. The total information content for each indicator is calculated by multiplying its variability and conflict. Finally, the weights are derived by normalizing this information content (Table 3). \begin{table}
\begin{tabular}{c c c c c} \hline
**Average Value** & **Term (in a** & **Drilling Fluid** & **Grouting Final** & **Dry Material per** & **Permeability** \\  & **Mathematical Formula)** & **Consumption (m\({}^{3}\)/h)** & **Pressure** & **Unit Length (t/m)** & **Permeability** \\ \hline
0.097 &
\begin{tabular}{c} Drilling fluid \\ consumption (m\({}^{3}\)/h) \\ \end{tabular} & 0.5 & 0 & 0 & 0 \\ \hline
0.311 &
\begin{tabular}{c} Grouting final pressure \\ \end{tabular} & 1 & 0.5 & 1 & 0 \\ \hline
0.142 &
\begin{tabular}{c} Dry material per unit \\ length (t/m) \\ \end{tabular} & 1 & 0 & 0.5 & 0 \\ \hline
0.727 & permeability & 1 & 1 & 1 & 0.5 \\ \hline \end{tabular}
\end{table} 
Table 1: Calculation of weights for the PC.