# Accounting for Resilience in the Selection of R Factors for a RC Unsymmetrical Building
## 4 Conclusions  
In this study, the selection of appropriate R factors was performed for an unsymmetrical L-shaped RC building in accordance with resilience, performance level and ductility demand aspects. The study proposes a framework in the R factor selection, and it can be adapted to other irregular buildings since only the modelling and loading conditions will be varied for each type of building. The framework remains the same which proposes various recovery paths in the assessment of R factors with resilience considerations. The seismic response of the building has to be taken care of via proper selection of R factors. It is possible to consider the irregularity in the design level as did in the present study. To plan for post-disaster recovery, the building irregularity found using the R factor should be incorporated with resilience consideration. Though several codes are silent on the above aspects, the present study gives a detailed description about the basis of R factor selection in  
Figure 21: Comparison of unsymmetrical building resilience under unidirectional and bidirectional loading at DBE design level (in percentage). Figure 22: Comparison of unsymmetrical building resilience under unidirectional and bidirectional loading at MCE design level (in percentage). the design. In this study, the seismic performance of an unsymmetrical building subjected to unidirectional and bidirectional loadings at two design levels such as the DBE and MCE levels was assessed. Some of the major conclusions of the study are as follows. * All of the cases of the unsymmetrical building reported a moderate ductility requirement at the DBE design level for both unidirectional and bidirectional loadings. The building almost meets the high ductility demand and corresponds to R equalling 5 and 6 at the MCE design level. This demonstrates that the ductility demand rises as the R factor increases. Buildings with lower ductility demands are generally more affordable to construct. This aids in making the right choice of R factors for the building design. * A higher R factor has an impact on building performance levels due to higher ductility demand. The performance level at the DBE design level advances from the IO level (at R equals 3 and 4) to the IO-LS level (at R equals 5 and 6). The building performance level varied significantly (IO-LS level to CP-C level) from R = 3 to 6 at the MCE design level. Under bidirectional loading, the performance level of the building has higher R (R = 5 and 6) cases which lie at the C-D level. This shows that the building reaches a full collapse damage state without having any residual strength. This was due to the reduction in transverse member participation in structural stiffness due to a bidirectional loading effect at a higher R factor. Thus, in the case of unsymmetrical building, the bidirectional effect significantly alters the building performance level with a marginal increase in ductility demand. * Under both unidirectional and bidirectional loading conditions, with respect to the DBE and MCE design level, the loss of resilience (LOR) was less than 30% and 50% at R = 3 and 4 (Cases I and II), respectively. At higher R factors of 5 and 6, the LOR marginally increases with more than 50% LOR at the MCE design level. At unidirectional and bidirectional loadings, though the building at R = 5 and R = 6 suffers significant functionality loss at the MCE level, the building holds almost 50% resilience. However, the recovery of the building from that level may lead to higher retrofitting costs to recover back to its target performance level. * It was concluded that as the building reaches a higher ductility demand with a value of 4.98 at R = 5 along with a performance level at the CP-C level, the maximum R factor for the considered unsymmetrical building can be recommended up to 4 with respect to unidirectional loading.