Research On Continuous Rigid Frame Bridge Grider Design Parameter Optimization Based On Dynamic Response

The prestressed reinforced concrete continuous rigid frame bridge has the advantages of good integrity,large span capacity,reasonable force,reasonable cost,good construction technology,smooth driving,beautiful appearance and so on.Continuous rigid frame bridge is usually used in the main span in the 100m to 250m range of high pier large-span structure.However,the continuous rigid frame bridge in seismic design mainly uses conservative experience to design and calculation to verify.And some design flaws also did not attract enough attention,so the continuous rigid frame bridge for different parameters of the dynamic response research is very necessary.This paper based on the actual project of large span prestressed concrete continuous rigid frame bridge as the background,choosing Ratio of side to middle span、The beam bottom effect curve、The beam height of Block 0 and the height of middle beam as optimization variables.Considering the influence of the main beam parameters on the seismic response of the bridge,the influence of the transverse beam on the seismic response of the bridge and the structural parameters on the seismic response of the bridge are analyzed by orthogonal test.The main work is as follows:(1)Introduced the main seismic damage of the commonly used bridge,the development course of the Chinese and Japanese earthquake resistance norms,the experts and scholars at home and abroad on the bridge seismic research status,the bridge seismic analysis methods and optimization methods were briefly introduced.(2)Summarize the parameters of the continuous rigid frame bridge which has been built at home and abroad,and obtain range of application.According to the seismic fortification level of the selected engineering background,a number of different objective functions are selected.Establishing 25continuous rigid frame models with different parameters,The seismic wave is selected by the same "longitudinal + horizontal + vertical" combination.According to the different optimization goals,the combination of optimal parameters are found in the elastic state and the elastic-plastic state.Through the range analysis and the variance analysis,the effect of each parameter on the seismic effect of the bridge is found out.(3)Only consider the number of transverse beams in the lower structural parameters,and establish different models.The seismic wave is selected by the same "longitudinal+ horizontal + vertical" combination.The results show that the final number of transvers e beams is obtained for different objective functions under elastic state and elastic-plastic condition.(4)The parameters of the main beam and the number of transverse beams are unified as structural parameters.Establishing 25 models with orthogonal parameters.The same"longitudinal + transverse + vertical" combination is used for seismic waves.Aiming at the different objectives of the selection,the optimal parameter combination in the plastic stage is found out.Through the analysis of the difference,the effect of each parameter on the seismic effect of the bridge is found out.