Compatibility charts of BRB-VD combined systems for RC frames in ultra-high seismic intensity zones

Abstract

The combined seismic energy dissipation of BRB and VD in ultra-high seismic zones leverages their strengths, producing a hybrid damping system with excellent performance and significant application potential. Although the potential of such combined damping systems in seismic design is widely recognized, the lack of a clear methodology for coordinating their distinct stiffness and damping mechanisms remains a major barrier to their effective implementation. To solve the compatibility issue between the two technologies, we perform a series of computational analyses of reinforced concrete frame structures equipped with BRB-VD combined systems in ultra-high seismic zones. The analysis determines key parameters, including the nominal lateral stiffness ratio K of BRBs and the additional damping ratio ξ_a provided by VD. As a result, the K-ξ_a relationship charts illustrating the compatibility between the two dampers under different seismic design groups in ultra-high seismic zones are developed, eliminating the inconvenience caused by multiple iterations based on the response spectrum design method. The accuracy and practicability of the K-ξ_a relation charts for combined seismic energy dissipation design are further validated through engineering examples, providing a convenient manual calculation tool for structural engineers and offering valuable references for similar high-seismic regions aroundthe world.