Evaluation of energy-dissipating devices in high-rise RC core wall buildings

Energy-dissipating devices (EDDs) are used to control the dynamic response of high-rise buildings in moderate to severe seismic risk areas. These systems can be effectively analysed using a rigorous non-linear response history analysis (NLRHA) procedure. However, expertise and time is required to perform and interpret the results from this procedure since several trials are required to select the most effective size and location of the dampers. In this study, the validity of the modal strain energy (MSE) method and the logarithmic decrement (LD) method was checked using a case study of a 40-storey reinforced concrete (RC) core wall building equipped with buckling-restrained braces (BRBs) and fluid viscous dampers (FVDs). Linear and non-linear models of the building including dampers were prepared. The elastic dominant modes and their target displacements were then determined using a response-spectrum analysis procedure. The MSE and LD methods were used to determine the equivalent damping ratio and the time period for BRBs and FVDs, respectively. The base shear and roof displacement, determined using modal and spectral parameters against these damping and time = period values, were found to match those determined using NLRHA with an accuracy of 5-10% and 20-30%, respectively. This study is helpful for the preliminary sizing of EDDs.