## 4 Results  
Figure 8 shows the pushover curves of the benchmark building BM0 in the x-x direction and in the y-y direction. It is observed that, for a drift level of 2% (displacement at the top of the building equal to 18.4 cm), the base shear load is equal to 2350 kN and 2500 kN in the x-x and y-y directions, respectively. The building no longer meets the requirements of current anti-seismic regulations, as it was calculated the appropriate/needed seismic base shear as \(\Sigma\)F\({}_{\rm{needed}}\) = 4007.20 kN in each direction. Figure 8: Pushover curves of BM0: (**a**) x-x direction; (**b**) y-y direction. Figure 7: Redesign of building BM2 (**a**) x-x direction; (**b**) y-y direction. In the x-x direction, it is noticed that the hinges of the columns remain in the Life Safety (LS) performance level, so the building has not suffered substantial damage due to the horizontal displacement of 18.4 cm at the top of the building (Figure 9a). In the y-y direction, the columns of the ground floor have not suffered substantial damage (IO), but the columns of the first floor are in the yellow zone (C), which means that several failures have occurred (Figure 9b). In the y-y direction, the building remains in the LS zone with a displacement of 16.7 cm at the top of the building. Figure 10 shows the plastic hinges of the RD1 building without the installation of CAR1 dampers for the displacement level of 18.4 cm at the top of the building, and it shows the axial load-displacement curves for the steel diagonal braces of the ground and first floor. It is noticed that the steel diagonal braces were buckling under compression, their most common problem [28; 29; 30], equal to 990 kN for the brace of the ground floor with a displacement of 3.7 cm at the top of the building (drift = 0.4%) and 610 kN for the brace of the first floor with a displacement of 3.1 cm at the top of the building (drift = 0.38%). The aim of the CAR1 is to protect the braces from buckling and also to dissipate energy [23; 31]. In order to select the appropriate characteristics of the CAR1 dampers, we used the tables and diagrams proposed by [PERSON] et al., who offer a wide variety of choices [21; 23]. The selected characteristics are presented in Table 2 for RD1. For the ground floor, it is selected a damper with an external diameter of 22 cm based on the diameter of the steel diagonal braces, and for the first floor, a damper with a diameter of 17.5 cm. For the ground floor, in the x-x direction, eight groups of superimposed steel blades with four blades with thicknesses of 12.5 mm constitute CAR1, and in the y-y direction, it is used only seven groups of blades with the same characteristics. For the first floor, eight groups of steel superimposed blades with four blades with thicknesses of 17.5 mm constitute the CAR1 damper in both directions. An appropriate configuration/geometry in the area of the stoppage bolt (oval hole) eliminates any additional compression forces on the  
Figure 9: Plastic hinges of BM0 for a displacement level of 18.4 cm at the top of the building: (a) x-x direction; (b) y-y direction. diagonal elements and allows only tensional forces to be developed (dc > dt). Therefore, the restraining bolt needs to be activated before the horizontal displacement of 3.7 cm and 3.1 cm (at the top of the building), which is equal to 4.4 cm of displacement parallel to the axes of the damper for the ground floor and 3.7 cm for the first floor in the x-x direction. The selected characteristics of the CAR1 dampers are presented in Table 3 for RD2. In this study, to highlight the variety of dampers, we chose different characteristics for each direction for the RD2 building, but to reduce the cost, having the same characteristics is usually preferred. For the ground floor, it is selected a damper with diameter of 17.5 cm based on the diameter of the steel diagonal braces, and for the first floor, it is selected a damper with a diameter of 14 cm.