## 4 Analysis of Results and Discussion
### STRC Shear Walls Failure Modes Boundary Analysis  
Boundary analysis of the failure modes of STRC shear walls can help structural engineers to better predict the failure modes of the walls and provide references for the corresponding design and strengthening. While flexural failure (F) and shear failure (S) of STRC shear walls are easily identified, flexural shear failure (FS) is often difficult to identify. Therefore, it is necessary to analyze the failure boundary conditions of SRCT shear walls. In this study, the relationship between the influence of the first six important features on the failure modes in the STRC shear walls was quantified, as shown in Figure 13. The horizontal coordinate indicates the value of the feature, and the vertical coordinate score represents the probability of occurrence. From Figure 13a, it can be seen that when \(\lambda\geq 1.5\), the score of flexural failure (F) occurs in STRC shear walls is close to 1, while the scores of shear failure (S) and flexural shear failure (FS) are negative, indicating that flexural failure is more likely to occur in STRC shear walls when \(\lambda\geq 1.5\). When \(0.90\leq\lambda\leq 1.50\), the score for flexural shear failure (FS) is greater than 0.5, and the score for shear failure (S) is about 0.1, indicating that STRC shear walls with \(\lambda\) in this range are more likely to have flexural shear failure (FS) and have a smaller probability of shear failure (S). When \(0.56\leq\lambda\leq 0.90\), shear failure (S) is more likely to occur. This is due to the fact that for higher or lower shear-span ratios (\(\lambda\)), many STRC shear walls are controlled by flexural moments or shear forces, respectively, while for moderate shear-span ratios (\(\lambda\)), many STRC shear walls are controlled by both flexural moments and shear forces. A similar analysis leads to a range of values for the remaining features for different failure modes,  
Figure 11: Ranking of important features of STRC shear wall failure modes.  
Figure 12: Ranking of important features for different STRC shear wall failure modes.  
as shown in Table 3. It should be noted that the range of values for this parameter is based on the STRC shear wall database established in this study, and further discussion may be required for values outside the range of parameters collected in the database. In general, the larger the shear-span ratios (\(\lambda\)) of STRC shear walls, the higher the probability of flexural failure. The greater the horizontal bars index in boundary element (\(\rho_{hc,fy_{4}}/f_{c}\)), vertical bars index in web (\(\rho_{vm,s}\,f_{y2}/f_{c}\)), and area share of webs (\(A_{w}/A\)), the greater the susceptibility of STRC shear walls to shear failure, while the greater the vertical bars index in boundary element (\(\rho_{vc,s}\,f_{y1}/f_{c}\)) and concrete compressive strength (\(f_{a}\)), the greater the susceptibility of STRC shear walls to flexural shear failure.  
Figure 13: Dependency diagram of the first 6 important features in the STRC shear wall damage model: (**a**) \(\lambda\); (**b**) \(\rho_{hc,c}\,f_{y4}/f_{c}\); (**c**) \(\rho_{vc,s}\,f_{y1}/f_{c}\); (**d**) \(f_{a}\)(MPa); (**e**) \(\rho_{vw,s}\,f_{y2}/f_{c}\); (**f**) \(A_{w}/A\).