Research On Seismic Response Of The Base Swing Isolation Pier

In a rare earthquake, swing can occur at the separation surface between the pier and thebase of a base swing seismic isolation pier. Part of the seismic energy is filtered by the swing,achieving the purpose of protecting both the base and the pier. This paper focuses on theresponse of a base swing seismic isolation pier to an earthquake. The research work is asfollows:1. Introduced the research achievement of the scholars both at home and abroad inseismic isolation at the base, summarized the control types of the seismic isolation and theirrespective characteristics.2. Described the basic principles of the seismic isolation device, introduced theadvantages of the seismic isolation system: When a strong earthquake comes, the impact ofthe seismic oscillation on the superstructure will be reduced through the isolation layer, thesuperstructure can work properly, which can ensure its favorable characteristics of safety ofthe building during the earthquake, no need of repair after the earthquake, economicfeasibility etc.3. Introduced the characteristics of several major collision models; adopted the models ofKelvin and Maxwell in which the energy loss in the process of collision can be considered;established the calculation model and motion equation of the base swing seismic isolation piertaking into consideration of collision effects; analyzed the calculation method and the datarange of the stiffness of connecting spring and the damping coefficient.4. Based on No.1grand bridge of Yangbi of the newly built railway from Dali to Ruili,established the single pier model and calculated the natural vibration characteristics of thestructure by adopting the finite element analysis software of Midas-Civil.5. For the base swing seismic isolation pier with consideration of the effect of collision,carried out the nonlinear time history response analysis under the impact of a rare earthquake;compared respectively with the two-spring model without consideration of the effect ofcollision and with the traditional high pier model.6. Focused on the research of the impact of the stiffness of spring and the value ofdamping coefficient of the models of Kelvin and Maxwell on the seismic response of a swingisolation pier, analyzed the differences of the seismic responses of the two models under astrong earthquake. On the basis of the two spring model, put forward a reasonable analyticalmodel of vibration reduction and isolation of base swing seismic isolation pier withconsideration of the effect of collision.