Research On Static And Dynamic Performance Of Railway Hybrid Girder Cable-Stayed Bridge Based On Dynamic And Static Load Test

Since its emergence in the 1970 s,hybrid girder cable-stayed bridges have been widely used in the field of highway and bridge construction due to their large lateral stiffness,good economy,reasonable structural stress,and good harmony between shape and environment.Compared with highway bridges,railway bridges have larger loads and stronger dynamic responses.Before Yongjiang River Bridge,there were no engineering practice examples of long-span railway hybrid girder cable-stayed bridges in the world,and there was a lack of targeted research materials.Based on the field test of Yongjiang River Bridge on Ningbo north ring road,the dynamic and static load test of long-span hybrid girder cable-stayed bridge was studied.Combined with the structural characteristics of the Yongjiang River Bridge,this paper studied the finite element analysis method of the whole bridge and the development of the dynamic and static load test scheme.Based on the theoretical data obtained by the finite element method,a dynamic and static load test plan was developed and practiced.The initial elevation of the bridge deck,the initial line shape of the pylon and the dead load cable force value were tested and compared with the design value analysis and used as the initial data for subsequent tests.The deformation and internal force of the bridge structure under the static test load are measured,and the design requirements are met through the inspection.The measured values of stress,deflection,tower top deviation and cable force test results of the test section were compared with the theoretical calculation values,and the check coefficient was obtained.The true bearing capacity of the bridge was evaluated.Through the analysis of dynamic and static load test results,the working performance of Yongjiang River Bridge is comprehensively evaluated,and the working condition of the bridge meets the design requirements.This paper summarized the experience of dynamic and static load test of long-span railway hybrid girder cable-stayed bridge and put forward some suggestions for improvement.