# Study on the Distribution Law of Crustal Stress in Fault Fracture Area
## 3 Stress Change Results  
The stress distribution was evaluated under various operating conditions, and the unit stress scenario was extracted, as illustrated in Figure 3. In this figure, \(\sigma_{1}\) denotes the maximum principal stress traversing the fault zone horizontally at different locations, while \(\sigma_{3}\) represents the minimum principal stress. Additionally, the variation in the direction of \(\sigma_{1}\) is also considered. The outcomes of the analysis are presented in Figures 4-7. \begin{table}
\begin{tabular}{c c c c} \hline
**Working Condition** & \(P\) **(\%)** & \(E_{r}/E_{f}\) & \(\alpha\) (\({}^{\circ}\))** \\ \hline No. 1\(\sim\)No. 16 & 0 & 1, 2, 3, 4 & 0, 30, 60, 90 \\ No. 17\(\sim\)No. 32 & 5 & 1, 2, 3, 4 & 0, 30, 60, 90 \\ No. 33\(\sim\)No. 48 & 10 & 1, 2, 3, 4 & 0, 30, 60, 90 \\ No. 48\(\sim\)No. 64 & 15 & 1, 2, 3, 4 & 0, 30, 60, 90 \\ \hline \end{tabular}
\end{table} 
Table 2: Variable Values of the Model under Different Operating Conditions. Figure 2: Schematic diagram of model stress. Figure 4: Stress distribution when the degree of fault fragmentation \(P=0\). Figure 3: Model stress extraction location. Figure 5: Stress distribution when the degree of fault fragmentation \(P=5\). Figure 6: _Cont_. Figure 6: Stress distribution when the degree of fault fragmentation \(P=10\). Figure 7: _Cont_. Based on the analysis of the aforementioned \(\sigma_{1}\) change law, it can be observed that under the conditions of \(P=0\) and \(\alpha=0^{\circ}\), the stress inside the fault increases, but the presence of crushed rock causes significant fluctuations in internal stress. Figure 9 highlights the stress point of the downward fluctuation of the curve (which does not exist when \(P=0\)) and reveals a corresponding relationship with the position of the corresponding crushed rock. The larger the crushed rock content, the more frequent the curve fluctuation, indicating that crushed rock has a pronounced impact on the stress distribution within the fault. Specifically, the magnitude and direction of stress near the crushed rock fluctuate, resulting in opposite patterns of stress variation under \(P=0\) conditions when compared to the stress change in the absence of fracture in the fault. Through qualitative understanding and numerical experimental analysis, it is evident that faults significantly disrupt the direction of local stress fields and exhibit consistent changes based on factors such as the angle between the maximum principal stress direction and the fault plane, the modulus ratio of faults to the surrounding rock, and the proportion of principal stress. When utilizing measured point data affected by faults in inversion calculations, it is crucial to consider the disturbance pattern to avoid distorted and non-uniform inversion stress fields. Therefore, understanding the disturbance patterns described in this section can serve as a basis for identifying abnormal measured in situ stress data influenced by faults prior to inversion analysis. When faults slide under the compression of the stress field, they reach an equilibrium stress state, which represents the initial stress field following the fault disturbance. Since faults primarily impact the local stress field, the stress field with faults can be considered as a local adjustment to the regional stress field after the fault occurrence. The investigation conducted in Section 3 can also be interpreted as examining changes in the local stress field before and after the occurrence of a fault. It is evident that accurate load conditions must be employed to describe the regional stress field before the fault occurrence during the inversion calculation of small fault-inclusive models. The stress field primarily arises from self-weight and tectonic actions. The key to the secondary inversion calculation of small fault-inclusive models lies in extracting appropriate structural load conditions from the results of the primary inversion analysis.