## 2 Materials and Methods
### Nonlinear Modeling and Determining Collapse Points of Structures
In their context, for the 7-story new buildings, they identified the immediate occupancy (IO) threshold as 0.43% and the Collapse Prevention (CP) threshold as 1.40%. For the older 7-story buildings, these values were calculated as 0.38% and 0.83%, respectively. For the 4-story models, the IO and CP thresholds were found to be 0.54% and 1.48% for the new buildings and 0.51% and 1.17% for older buildings. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Damage Level** & **Concrete Limit State** & **Steel Limit State** \\ \hline Limited Damage & \(\epsilon_{\text{cLD}}\) = 0.0025  & \(\epsilon_{\text{s}}\) = 0.0075 \\ Significant Damage & \(\epsilon_{\text{cSD}}\) = 0.75 \(\epsilon_{\text{cCP}}\)6  & \(\epsilon_{\text{sSD}}\) = 0.75 \(\epsilon_{\text{sCP}}\)6  \\ Collapse Prevention & \(\epsilon_{\text{cCP}}\) = 0.0025 \(+\) 0.04\(\sqrt{\textit{{{{{wwe}}}}}}\)\(\leq\) 0.018  & \(\epsilon_{\text{s}}\) = 0.4 \(\epsilon_{\text{su}}\)\(\text{b}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The damage limits specified in TBEC-2018. Figure 4: Capacity information (immediate occupancy and ultimate capacity) of 3-story buildings. Figure 5: Capacity information (immediate occupancy and ultimate capacity) of 4-story buildings. Figure 3: Capacity curves and associated damage states for 6N3 model in X (**right**) and Y (**left**) directions. In the present study, the mean IO threshold for the new 4-story reinforced concrete buildings was calculated as 0.3%, while the CP threshold was found to be 1.7%. For the older 4-story buildings, the corresponding values were 0.4% for IO and 1.4% for CP Regarding the 7-story buildings, the IO threshold was determined as 0.3% for the older buildings and 0.4% for the new buildings, whereas the CP thresholds were calculated as 1.1% for the older and 1.9% for the new buildings (Table 3). However, it is important to note that this study defined collapse based on the _ultimate_ state--representing a pancake-type  
Figure 8: Capacity information (immediate occupancy and ultimate capacity) of 7-story buildings. Figure 6: Capacity information (immediate occupancy and ultimate capacity) of 5-story buildings. Figure 7: Capacity information (immediate occupancy and ultimate capacity) of 6-story buildings. Figure 9: Capacity information (immediate occupancy and ultimate capacity) of 8-story buildings. failure scenario in which one of the columns completely loses its load-bearing capacity. As readers may appreciate, this definition was adopted to avoid conflicts with the provision in the ref [9; 10] stating that \"_the ratio of beams beyond the CP region shall not exceed 20% in any story_\". Therefore, the collapse drift limits (\(\Delta_{\text{u}}\)) defined in this study corresponded to more severe damage states than the CP thresholds reported in [17]. In this study, the Newmark-Beta method [20] was employed for time history analysis. To ensure unconditional stability, the Gamma (\(\gamma\)) and Beta (\(\beta\)) coefficients were set to 0.5 and 0.25, respectively. Rayleigh damping was used to formulate the damping, with the damping ratio assumed to be 5%. The mass and stiffness proportional coefficients were determined based on different period values and considered for the viscous proportional damping. When determining the number of modes considered in this study, it was ensured that the mass participation rate of the modes exceeded 95%, which corresponded to the first 8 modes in this study.