# Accounting for Resilience in the Selection of R Factors for a RC Unsymmetrical Building
## 3 Design Concept and Structural Details of the Building
### Performance Level of the Building  
The extent of the building damage caused by the earthquake determines the structure level of performance. Immediate occupancy (IO), life safety (LS) and collapse prevention (CP) are three different performance levels (Figure 9). According to the American Society of Civil Engineers [54], the member non-linearity was accounted for in the form of plastic hinges. To assess the non-linear behaviour of the structure, plastic hinges were placed on the structural parts, such as beams and columns. With the structural member non-linearity, the NLTHA was performed to assess the structural capacity and performance level. The rotational capacity and constraints of the plastic hinges form the basis of the non-linear behaviour of the structure. The study considered the plastic hinge rotation limitations of 0.01, 0.025 and 0.050 for IO, LS and CP levels, respectively. From the NLTHA, the building performance level was found at each design level under both unidirectional and bidirectional loading conditions (Tables 8 and 9). The schematic representation of the performance point location of each building case with respect to MCE design level at both unidirectional and bidirectional loading conditions was shown in Figures 10 and 11, respectively. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**S. No.**} & \multirow{2}{*}{
\begin{tabular}{c} **Design** \\ **Level** \\ \end{tabular} } & \multicolumn{4}{c}{**Ductility Demand (\(\mu_{\text{D}}\))**} \\ \cline{3-6}  & & **R = 3** & **R = 4** & **R = 5** & **R = 6** \\ \hline
1 & DBE & 1.58 & 1.81 & 2.15 & 2.42 \\
2 & MCE & 3.45 & 3.79 & 4.98 & 5.53 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Ductility demand at each building case under unidirectional loading. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**S. No.**} & \multirow{2}{*}{
\begin{tabular}{c} **Design** \\ **Level** \\ \end{tabular} } & \multicolumn{4}{c}{**Ductility Demand (\(\mu_{\text{D}}\))**} \\ \cline{3-6}  & & **R = 3** & **R = 4** & **R = 5** & **R = 6** \\ \hline
1 & DBE & 1.67 & 1.92 & 2.30 & 2.58 \\ \hline
2 & MCE & 3.67 & 4.10 & 5.18 & 5.80 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Ductility demand at each building case under bidirectional loading. Figure 9: Generalised force deformation curve as per ASCE 41–17 [54]. According to Table 8, the building performance level is impacted by changes in the R factor. At the DBE design level, the building lies at the IO level at R = 3 and 4, while at R = 5 and 6 it almost reaches the LS level. At the MCE design level (Figure 10), the  
Figure 11: Schematic representation of variation in the building performance level with respect to R factors at the MCE design level under bidirectional loading. Figure 10: Schematic representation of variation in the building performance level with respect to R factors at the MCE design level under unidirectional loading. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**S. No.**} & \multirow{2}{*}{**Design Level**} & \multicolumn{4}{c}{**Performance Level**} \\ \cline{3-6}  & & **R = 3** & **R = 4** & **R = 5** & **R = 6** \\ \hline
1 & DBE & IO & IO & Almost LS (IO \(\leq\) LS) & Almost LS (IO \(\leq\) LS) \\ \hline
2 & MCE & IO-LS & Almost CP (LS \(\leq\) CP) & CP-C (CP \(\leq\) C) & CP-C (CP \(\leq\) C) \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Performance level at each building case under unidirectional loading. building reaches IO-LS, almost CP, CP-C and CP-C at R equal to 3, 4, 5 and 6, respectively. It was observed that, at each R factor, the performance level was maintained to limit the ductility demand. At higher R factors (R = 5 and 6), the building lies at the CP-C level. This demonstrates how a greater R factor influences a building performance level because a higher R value calls for more ductility. In the case of bidirectional loading, the building performance reduces significantly when compared with unidirectional loading (Table 9).