# Deterministic Discrete Fracture Network Model and Its Application in Rock Mass Engineering
## 3 Example Verification
The cosine correction factor for the dip direction and angle is 0.5, leading to a structural plane model size of 3.5 m. However, Table 1 does not explicitly specify the exact relationship between spacing (0.4 m), volumetric density (0.27), and model size. Therefore, establishing an \"MS1-LP1\" model is considered the most appropriate choice. The average size of the disk model is 3 m. Thus, the center coordinates of the disk model can be obtained through calculations based on formulas 4, 5, and 6. For layers and faults, there is no need to perform such calculations. The subsequent analysis will use General Block to evaluate the degree of blockiness; the parameters of the three structural surface models are shown in Tables 6 and 7. In General Block, the rock mass model can only be built in the second quadrant. So, it is necessary to process the model parameters to ensure they conform to the coordinate system of the General Block. When using it, pay attention to adjusting the coordinate system, the parameters of the structural plane, and the relative position of the rock mass model. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Joint**} & \multicolumn{2}{c}{**Center**} & \multicolumn{2}{c}{**Dip**} & \multicolumn{2}{c}{**Dip**} & \multirow{2}{*}{**Joint**} & \multicolumn{2}{c}{**Center**} & \multicolumn{2}{c}{**Dip**} & \multicolumn{2}{c}{**Dip**} \\  & \multicolumn{2}{c}{**Coordinates (m)**} & \multicolumn{2}{c}{**Direction (\({}^{\circ}\))**} & \multicolumn{2}{c}{**Angle (\({}^{\circ}\))**} & & \multicolumn{2}{c}{**Coordinates (m)**} & \multicolumn{2}{c}{**Direction (\({}^{\circ}\))**} & \multicolumn{2}{c}{**Angle (\({}^{\circ}\))**} \\ \hline
1 & \(-\)4.47 & 5.00 & 5.40 & 90.47 & 59.69 & 11 & \(-\)3.92 & 5.51 & 1.36 & 92.16 & 50.47  
Since the persistence of the sampling window is 5 m \(\times\) 5 m, a 5 m \(\times\) 5 m observation window is set every 0.5 m in the X direction starting from the origin, as shown in Figure 10 below. The layer and fault models penetrate the entire rock mass, so it is only necessary to observe the persistence of the joint model within the rock mass. The coordinate system in the figure is that of the software General Block. After selecting the starting point of the observation window, the window can be set along the direction perpendicular to the X-axis. Due to the large number of observation window settings, only a portion of the observing results will be displayed. In the following text, it can be seen that the structural surfaces do not vanish at the points (0, 0, 0) and (\(-\)3, 0, 0). Therefore, it is necessary to expand the model in the X direction. When we continue to set up observation windows at (1, 0, 0) and (\(-\)4, 0, 0), it is found that the structural surfaces vanish, as shown in Figure 11.  
Therefore, the X-direction dimension of the bedrock model is set to 5 m to ensure complete cutting. Through observation, it was found that the structural surfaces within the observation windows at the starting positions of (\(-\)1.5, 0, 0) and (\(-\)2, 0, 0) did not completely vanish in the Y direction. Thus, it is necessary to expand the observation windows to locate the vanishing positions. The original 5 m \(\times\) 5 m windows were extended by 1 m to both the left and right. The distribution of structural surfaces within the observation windows after modifying the starting positions and window persistence is compared with the unmodified case, as shown in Figure 12.  
By comparison, it can be seen that after expanding by 1 m in the Y direction, most of the structural surfaces vanished within the observation windows. Therefore, it is reasonable to expand the bedrock model by 1 m to both the left and right in the Y direction. Similarly, observing the original observation windows reveals that the structural surfaces within the observation windows at (\(-\)2, 0, 0) and (\(-\)2.5, 0, 0) did not completely vanish in the Z direction.