Experimental and numerical study of beam-through energy-dissipative rocking columns for mitigating seismic responses

Abstract

The Energy Dissipative Rocking Column is a novel seismic mitigation device that could effectively mitigate maximum inter-storey drift and drift concentration of low-rise buildings under earthquakes. This study proposed a beam-through configuration for the connections between steel frames and Energy Dissipative Rocking Columns (EDRCs) to reduce the necessary workload in the application of EDRCs. The study commenced with a cyclic loading test on a substructure composed of the beam-through EDRC and frame beam-to-EDRC connections. Following the cyclic loading test, a simplified numerical model of the beam-through EDRC was built and validated against the test results. Finally, parametric studies were conducted to determine the seismic demand on the beam-to-EDRC connections. The results showed that the beam-through EDRCs have acceptable lateral resisting and energy dissipation capacity. The simplified numerical model could reasonably well predict the hysteretic behaviour of the specimens with and without the steel damper. The parametric study results, based on hundreds of nonlinear time history analyses, indicated that increasing connection stiffness in the range of 0 to 1.5 is most effective in mitigating both maximum drift and drift concentration. Moreover, the beam-through EDRC has very close effectiveness with the conventional column-through EDRC when the connection stiffness ratio is close to or larger than 4.