| A new hybrid ductile-rocking (HDR) seismic-resistant system is proposed which consists of a code-designed buckling-restrained braced frame (BRBF) that is free to rock on its foundation. The goal of this system is to reduce the disadvantages associated with BRBFs, such as excessive drift concentrations and residual deformations, while maintaining their reliable limit on forces and accelerations. A lockup device ensures the full code-compliant strength at a predetermined column uplift, and supplemental energy dissipation elements reduce the overall response.;Buildings of 2, 4, and 6-storeys in height were designed for Los Angeles, California, and studies were performed to investigate how the energy dissipation strength, lockup base rotation, and vertical mass modelling choices affected the system's performance and dynamic response. An example detail was developed that included a cast steel energy dissipating device. These studies showed that the HDR system achieved a significant reduction in brace damage over conventional BRBF structures. |
