## 4 Results and Discussion
### Results of Incremental Dynamic Analysis  
The results of the incremental dynamic analysis (IDA) were obtained by applying seven pairs of ground motion records to each archetype in both analysis directions. This resulted in 14 curves per archetype for each direction. The FEMA P695 methodology recommends using a larger number of ground motions, including a variety of records representing different seismogenic sources and soil types. In the present study, a reduced number of records was employed, as all records were selected from subduction-zone events recorded on stiff soils (soil type C according to the Chilean seismic code NCh 433 [1]). This soil type corresponds to dense soil deposits with an average shear wave velocity in the upper 30 m (\(Vs30\)) ranging from 350 m/s to 500 m/s, which represents relatively stiff ground conditions. While the selected ground motions corresponded to recordings on stiff soils (soil type C) with relatively uniform conditions, it should be noted that the effects of topographic amplification, such as wave trapping, focusing, or reflection due to terrain geometry, were not explicitly included. This omission was a methodological decision, as its inclusion would have required advanced 2D or 3D seismic ground response modeling coupled with the structural system analysis, which was beyond the scope of this study. Consequently, potential increases in the seismic demand associated with topography-induced amplification were not directly considered, although the geometric effects of slope on the structural configuration and performance were explicitly addressed. It should be noted that the use of ground motions matched to the MCE spectrum represented a deviation from the standard FEMA P695 procedure, which typically relies on unmodified real records to preserve record-to-record variability. Nonetheless, this decision was based on findings from a previous study by [PERSON] et al. [77], in which incremental dynamic analysis was applied to reinforced concrete shear wall buildings using Chilean subduction records. The study reported two main challenges: high dispersion in the IDA curves and difficulties in achieving convergence during nonlinear analyses. By applying spectrum matching, both the dispersion of the response curves and the numerical convergence were slightly improved. Therefore, although the approach used in this study deviated from the FEMA's original formulation, it enhanced the numerical stability and consistency under site-specific seismic demand conditions. From the IDA curves shown in Figure 15, the collapse point was identified as the point at which the slope of the curve was equal to or less than 20% of its initial slope. Once the collapse points were established, the value of the collapse safety target (\(CST\)) was determined as the ground motion intensity at which more than half of the curves (i.e., the median plus one) had reached collapse. Figure 14: Period-based ductility for the archetypes in both directions of analysis. Figure 15: Incremental dynamic analysis (IDA) curves showing the values of SCT and SMT for the archetypes: (**a**) 0\({}^{\circ}\) in x-direction, (**b**) 0\({}^{\circ}\) in y-direction, (**c**) 15\({}^{\circ}\) in x-direction, (**d**) 15\({}^{\circ}\) in y-direction, (**e**) 30\({}^{\circ}\) in x-direction, (**f**) 30\({}^{\circ}\) in y-direction, (**g**) 45\({}^{\circ}\) in x-direction, and (**h**) 45\({}^{\circ}\) in y-direction. Among all the results obtained from the IDA curves, the methodology required only the identification of the median collapse intensity \(\hat{S}_{CT}\). An efficient way to determine this was by scaling all selected ground motion records relative to the maximum considered earthquake (\(MCE\)), whose intensity is denoted as \(S_{MT}\), and initiating the analyses from this intensity level until at least half of the scaled ground motions produced collapse. The lowest intensity level at which half of the ground motions caused collapse was considered the median collapse intensity \(\hat{S}_{CT}\).