A Study of Integrated Structural Control Systems for Multi-Hazard Response Mitigation

Abstract

<p>Dynamic Vibration Absorbers (DVA), including Tuned Mass Dampers (TLD) and Tuned Liquid Dampers (TLD) have been successfully employed to reduce excessive wind-induced resonant vibration motions in flexible structures. A limited number of studies have focused on utilizing TMDs in base isolated structures to reduce resonant motions resulting from multi-hazards (both wind and seismic excitation). A recent study has investigated the wind-induced response of a base isolated (BI) structure with a TLD under wind loading, however, its response under seismic excitation was not considered. The focus of this research was on the behaviour of coupled passive structural control base isolation systems under base excitation with particular attention on a BI-building-TLD. A series of shake table tests were conducted on a base isolated scale-model building with a TLD system mounted on its roof. The isolation system comprised of stable unbonded-fiber reinforced elastomeric isolators (SU-FREI). Tests, with and without liquid in the TLD system, were carried out to evaluate the influence of the TLD under both harmonic base excitation and earthquake excitation at various excitation amplitude levels. An existing BI-structure-DVA numerical model was modified to incorporate a multi-parameter isolator model (Backbone Curve model) to simulate the behaviour of a SU-FREI isolation system and was evaluated using results from the shake table study. The BI-structure-DVA numerical model was used to carry out a preliminary investigation on different combinations of linear and nonlinear base isolators with linear and nonlinear DVA under harmonic excitation. An iterative updating scheme was added to the numerical model to simulate the amplitude dependent behaviour of SU-FREI under earthquake excitation and this updated model was then used to investigate the performance of the BI-building-TLD and a linear BI-building-TLD under different earthquake ground motions.</p>