# Accounting for Resilience in the Selection of R Factors for a RC Unsymmetrical Building
## 2 Building Description and Seismicity Conditions  
A high-rise, G+10-storey, L-shaped, unsymmetrical, reinforced, concrete building was considered in this study. The total plan area of the building is 324 m\({}^{2}\). The plan and elevation of the unsymmetrical building are shown in Figure 1, while its 3D view is shown in Figure 2. The total height of the building is 44 m (Figure 1b) with an inter-storey height of 4 m. The collapse phenomenon is the combination of plastic and dynamic behaviour of the structural members. Though distributed plasticity provides slightly better results, in terms of modelling difficulties the default plastic hinges are assigned as per ASCE 41-17. The hinges were assigned in beams and columns at the starting and end portion of the member. The beam elements were assigned with M3 hinges, whereas for columns it was P-M2-M3 hinges. In the study, the lateral load-resisting system with bracings, URM infills, etc., was not included. The slab members were provided along with the rigid diaphragm action which was considered at each floor level that inhibited the actual behaviour of the building.  
The building was designed in accordance with IS: 456-2000. The self-weight of concrete members such as beams, columns, slabs, and walls is included in the dead loads. Consideration was given to the wall load on the outside margin and the 150 mm slab thickness. The wall is 230 mm thick, and a floor finish of 1.5 kN/m\({}^{2}\) was taken into account. A live load of 3 kN/m\({}^{2}\) and a live roof load of 0.75 kN/m\({}^{2}\) were also considered. For beams and columns, the concrete grades M25 and M30, respectively, were taken into consideration, and steel reinforcement with a 500 MPa yield strength was employed, while 5% damping with medium soil (Type II) was assumed according to IS 1893:2016 (Part I). Five various ground motions, namely El Centro, Bam, Kobe, San Fernando and Tabas, were considered for the present study (Table 1), with the corresponding spectrum-compatible ground motion time histories sketched in Figures 3-7. Due to the asymmetry in the building orientation, unlike symmetrical building cases, the seismic loading was independently applied in both longitudinal (Ux) and transverse (Uy) directions. The behaviour of the building in both of the directions was therefore observed.  
\begin{table}
\begin{tabular}{c c c c c c} \hline
**Record** & **Event** & **Year** & **Magnitude ‘Mw’** & **Station** & **PGA (g)** \\ \hline
1 & El Centro, California & 1940 & 7.10 & Imperial valley & 0.319 \\
2 & Bam, Iran & 2003 & 6.60 & BAM & 0.969 \\
3 & Kobe, Japan & 1995 & 6.90 & KJMA & 0.821 \\
4 & San Fernando, California & 1971 & 6.61 & Pacoima dam & 1.171 \\
5 & Tabas, Iran & 1978 & 7.35 & TABAS & 0.861 \\ \hline \end{tabular}
\end{table}
Table 1: Ground motion details [46].  
Figure 1: Geometric orientation of unsymmetrical building: (**a**) plan view; (**b**) elevation.  
Figure 2: Three-dimensional view of L-shaped unsymmetrical building.  
Figure 4: Bam earthquake time history.  
Figure 5: Kobe earthquake time history.  
Figure 3: El Centro earthquake time history.  
Figure 6: San Fernando earthquake time history.  
The building was designed with different cases of R (R equal to 3, 4, 5 and 6), considering 1.5 as the importance factor (I) and 0.36 as the zone factor (Z). It is worth highlighting that the response reduction factor is R = V\({}_{\text{e}}\)/V\({}_{\text{d}}\), where V\({}_{\text{e}}\) is the elastic base shear and V\({}_{\text{d}}\) is the design base shear. The seismic behaviour of the building was analysed at each design level. The scale factor used is shown in Table 2 at design levels such as DBE and MCE levels.