Theoretical Study On Vertical Vibration Response Of The Ribbon Floating Bridge With Semi-rigid Connect Joint

This dissertation investigates the vertical vibration response of the ribbon floating bridge theoretically and numerically with taking into account the influence of connect joint. The results of the work can be offered as reference for the design and research of the assembling structure with connect joint such as ribbon floating bridge and prefabricated bridge. The main work and results include:(1)A kind of bending-resistant spring hinge model is introduced to simulate the transferring elasticity-bending moment property of connect joints, and the stiffness of the bending-resistant spring hing of ribbon bridge and detachable bridge for highway are presented. The bending-resistant spring hinge model is validated by the comparisons between analytical and the experimental results.(2)The beam model with bending-resistant spring hinges is developed for global calculation of ribbon floating bridge. Analytical solutions of the internal force and deformation of double-span beam with bending-resistant spring hinge on elastic foundation are derived. The transfer matrix method is used for analysing the multi-span beam with bending-resistant spring hinges on elastic foundation. The analytical and numerical results show that the semi-rigid property of connect joint should be taken into account when processing static analysis of the assembling structure as ribbon floating bridge.(3)Based on the model of beam with bending-resistant spring hinge on elastic foundation, the analytical solutions of free vibration of double-pontoon ribbon floating bridge are derived. Point matrixes of the bending-resistant spring hinge for free vibration analysis are developed, the influence of the stiffness of connect joint and the number of span on the free vibration property is studied by the transfer matrix method and finite element method. The results show that the property of free vibration is related to the number of ribbon floating bridge's span, even or odd, and that the semi-rigid property of connect joint should be taken into account in analysis of the free vibration.(4)Based on the model of beam with bending-resistant spring hinge on elastic foundation, the vibration response of ribbon floating bridge subjected to single-vehicle load, double-vehicle load and motorcade load are studied by the finite element method. Results show that the semi-rigid property of connect joint should be taken into account in analysis of the forced vibration, and that it can take the single-vehicle load as control load and take the section which is adjacent to the middle as control section in the global structure design of ribbon floating bridge for pedrail-load.