Analysis On Dynamic Characteristic And Seismic Isolation Of Simple Beam-arch Combined Bridge

As one of lifeline engineering Bridges was destroyed or collapsed by the earthquake,leading to traffic paralysis in the area.So after the earthquake relief work can not be carried out smoothly,exacerbated by secondary disasters,resulting in greater loss of life and property.To improve the seismic performance of Bridges,bridge isolation technology is an effective solution.On the basis of South river extra-large bridge,the present paper gives an analysis of seismic effects by using LRB as isolation unit.The main work of this paper includes the following aspects:1.On the basis of the research data at home and aboard,the present paper introduces the development and status quo of seismic isolation technology as well as comprehensive analysis of the LRB's structure,working principle,the mechanical properties and parameters calculation.2.Combined with practical engineering,according to the mechanics characteristics of the bridge,isolated and non-isolated space finite element model of South river extra-large bridge has been established by using ANSYS finite element software as well as discuss simplified processing and establishing method.The dynamic characteristics of two models respectively is calculated and compared.3.The seismic behavior of a isolated structure model and a non-isolated structure model is analyzed by using the seismic nonlinear dynamic time history analysis and the response spectrum respectively.The influence of LRB for the main sectioninternal force and node displacement is analyzed,and it is concluded that the lead rubber bearing the reduction of this kind of bridge vibration isolation effect.4.The bridge model of consider a united approach span is established,and the structural response of the model under the action of three-dimensional seismic force is calculated.At the same time,the influence ofapproach bridge about the main section internal force and node displacement is analyzed.