Response modification factors for RC case-study buildings with structural walls

A rational approach for determining the response modification factor, R, has been applied to reinforced concrete (RC) shear wall buildings designed under current codes and standards of practice. The approach is founded upon the performance-based evaluation framework from the SAC project; however, new values for various parameters were derived specifically for RC shear wall buildings because the SAC parameters were for steel moment frame buildings. Typical RC shear wall buildings were designed consisting of solid, flexure- dominated structural walls for lateral load resistance and a flat plate floor system for gravity loads. The performance of each building was then evaluated by calculating the confidence level of achieving the design objective. The buildings designed per the current R-value of 6 demonstrated good performances, meaning that the confidence levels of avoiding collapse were greater than the target value of 90%. The confidence levels for shear wall buildings with greater R-values were also determined, suggesting that further study could provide the basis for justifying an R-value of 7 for the special RC shear wall structural system.