## 4 Overview of Pseudo-Dynamic Testing and Result Analysis
### Specim Preparation and Parameters  
A domestic three-story RC school building frame (standard drawings of the 1980s) [46], as shown in Figure 10, was selected and used to verify the seismic performance of the proposed NBSD-based seismic retrofitting method. The story height is 3.3 m, the design concrete strength is 21 MPa. T-shape beams were used as each floor's beams, considering the effective slab width in accordance with KDS 41 [5].  
Figure 10: Cont.  
Figure 11a and 12a show the bar arrangement details of the existing frame with no reinforcement applied, along with an image of the corresponding specimen. For pseudo-dynamic testing, a test WSCS frame retrofitted using the proposed NBSD-based seismic retrofitting method was prepared, along with a test frame with no reinforcement applied for comparison, as shown in Figures 11a and 12a. These two test frames were subjected to the tests, and the results were compared.  
Figure 11: Bar arrangement details of the specimens: (**a**) existing frame with no reinforcement applied (PD-FR) and (**b**) frame retrofitted with NBSD-WSCS (PD-NBSD-WSCS).  
Figure 10: Images of target building and frames selected for pseudo-dynamic testing: (**a**) front view, (**b**) top view, and (**c**) 3D view.  
According to [PERSON] [45], the Hachinohe wave (EW) exhibited the largest seismic response displacement (ductility) among the ten historical seismic waves set for middle- and low-rise RC structures (whose proof stress is less than 0.5 in terms of shear coefficient). Thus, in the present study, the Hachinohe wave was selected as the input seismic ground motion for pseudo-dynamic testing. The input seismic acceleration was set by standardizing the Hachinohe wave (EW) into 200, 300, and 400 cm/s\({}^{2}\). Among them, 200 and 300 cm/s\({}^{2}\) are equivalent to two-thirds the seismic magnitude of an earthquake with a recurrence period of 2400 years (corresponding to Seismic Zone-1 and Soil Profile Type S\({}_{4}\) and S\({}_{5}\)) defined in KDS 41 [5]. Furthermore, 400 cm/s\({}^{2}\) was defined to examine the performance of the NBSD-based seismic retrofitting method proposed in the present study when a large-scale earthquake occurs. Thus, it corresponds to the seismic magnitude of an earthquake with a recurrence period of 2400 years. Figure 13 shows time history records of the normalized ground motion accelerations used in the pseudo-dynamic test, respectively, together with their acceleration response spectrum. The axial force was determined based on the axial load exerted on the actual existing frame (two columns), i.e., 1000-kN. Thus, each of the two columns was subjected to a constant axial force of 500-kN. Table 8 summarizes the applied specimen parameters.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Specimen Name** & **Test Method** & **Reinforcing Method** & **Input Seismic Wave Intensity** \\  & & & **(cm/s\({}^{2}\))** \\ \hline PD-FR & Pseudo-dynamic testing & - & 200 \\ PD-NBSD-WSC & Pseudo-dynamic testing & The NBSD-based window-type seismic control system & 200/300/400 \\ \hline \hline \end{tabular}
\end{table}
Table 8: Pseudo-dynamic testing specimens and the applied parameters.  
Figure 12: Images of the test specimens: (a) existing frame with no reinforcement applied (PD-FR) and (b) frame retrofitted with the NBSD-WSCS (PD-NBSD-WSCS).