## 5 Comparison of Structural Analyses under Different Earthquake Ground Motion Levels
The target displacements for damage estimation must be determined for the performance limits of structural elements in performance-based earthquake engineering. In this study, we used the limit states which are defined in Eurocode-8 (Part 3) [93; 94]. Table 10 gives the limit states for damage estimation in this code. Typical pushover and idealized curves as well as the calculated displacements are demonstrated in Figure 14. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Limit State** & **Description** & **Return Period** & **Probability of Exceedance** \\  & & **(Year)** & **(in 50 Years)** \\ \hline Limit state of damage & Only lightly damaged, damage to & & \\   limitation (DL) & non-structural components & 225 & 0.20 \\  & economically repairable & & \\ \hline Limit state of significant & Significantly damaged, some residual & & \\   damage (SD) & strength and stiffness, non-structural & & \\   damage (SD) & components damaged, uneconomic & 475 & 0.10 \\  & to repair & & \\ \hline Limit state of near collapse & Heavily damaged, very low residual & & \\  (NC) & strength and stiffness, large & 2475 & 0.02 \\  & permanent drift but still standing & & \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Limit states in Eurocode 8 (Part 3) [93; 94]. Figure 13: Column and beam cross-sections. Table 11 shows all target displacements obtained in the X direction in the sample RC building for all provinces in the region according to the last two seismic design codes. The DD-2 ground motion level was selected for comparison with the previous code. The fundamental natural period could be obtained by using eigenvalue analysis [95,96]. Based on the eigenvalue analysis, the natural periods were obtained as 0.55 s for the sample RC building. The same natural fundamental periods were obtained for all earthquake ground motion levels. The base shear forces for the sample structural model for each earthquake ground motion level were calculated. The comparison of the limit states of performance assessment for different earthquake ground motion levels is demonstrated in Figure 15. Table 12 lists all values obtained in the X direction. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Provinces**} & \multirow{2}{*}{**Code**} & \multicolumn{2}{c}{**Target Displacements (m)**} \\ \cline{3-4}  & & **DL** & **SD** & **NC** \\ \hline Agr & & 0.106 & 0.137 & 0.237 \\ \hline Ardahan & & 0.122 & 0.157 & 0.272 \\ \hline Bingöl & & 0.298 & 0.382 & 0.662 \\ \hline Bitlis & & 0.118 & 0.152 & 0.263 \\ \hline Elazig & & 0.176 & 0.225 & 0.390 \\ \hline Erzincan & & 0.270 & 0.347 & 0.601 \\ \hline Erzurum & & 0.217 & 0.278 & 0.482 \\ \hline Hakkari & & 0.145 & 0.186 & 0.322 \\ \hline Igdir & & 0.111 & 0.143 & 0.248 \\ \hline Kars & & 0.089 & 0.114 & 0.197 \\ \hline Malatya & & 0.158 & 0.203 & 0.352 \\ \hline Mus & & 0.149 & 0.191 & 0.331 \\ \hline Tunceli & & 0.158 & 0.203 & 0.352 \\ \hline Van & & 0.123 & 0.158 & 0.274 \\ \hline Bingöl, Bitlis, Erzincan, Hakkari, Malatya, Mus & TSDC-2007 & 0.182 & 0.233 & 0.405 \\ \hline Agn, Ardahan, Elazg, Erzurum, Igdir, Kars, Tunceli, Van & TSDC-2007 & 0.136 & 0.175 & 0.303 \\ \hline \hline \end{tabular}
\end{table} 
Table 11: Comparisons of target displacements. Figure 14: Typical pushover and idealized curves and calculated displacements. Since the structural characteristics were the same, the base shear force, elastic, and effective stiffness values were approximately equal to each other. The larger values of the design spectra significantly increased the demand displacements expected from the building. The increase in the PGA for each ground motion level was approximately equal to the increase in the displacement values obtained for the performance levels. The displacement values expected from the building increased depending on the magnitude of the earthquake.