Seismic Response of bi-directional based isolated Bridges

What is it about?

Special bridges, curved, skew and long-span bridges need particular attentions in their analysis, modelling, seismic design, and construction to maintain structures performance at earthquake exposure up to the expectations. Typically, these bridges exhibit complex behaviour in which the flexural and torsional vibration motions are strongly coupled that promotes much solicitude about their behaviours under environmental dynamic loads such as earthquake. Application of passive control system has been shown to be effective to protect bridges under seismic excitation. The accurate description of the shear force deformation responses of the base isolation bearings under bidirectional earthquake excitation loading is major for analysis and design of base-isolated bridges since the using un-coupled modelling approach with two separate unidirectional models could not accurately describe the bidirectional coupled behaviour of the isolation bearing. A simplified lumped mass model of target bridges is used to investigate the seismic response under bidirectional excitation either harmonic or real earthquake ground motions; the Bouc–Wen model is used to capture coupling feature of the shear force deformation behaviour. The seismic response demands of the bridge model with bidirectional interaction modelling approach are compared with those without interaction. Numerical results show that the isolated bridge is significantly influenced by the bidirectional interaction of bearing forces.

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