PC Box Girder’s Web Position Optimization And The Analysis Of The Longitudinal Prestressed Reinforcement’s Transverse Effect

With the development of Chinese bridge construction, large span, wide box and long cantilever are the requirements of PC box-girder Bridge’s development. So a more accurate design of continuous girder bridge is necessary. The spatial stress characteristic of Girder Bridge cannot be accurately reflected by the traditional beam elements’ analysis method. Especially the stress’ transverse distribution cannot be reflected. The finite element model is used to analysis the spatial stress characteristic of Girder Bridge instead of the traditional beam elements’ analysis method. The mainly works of the essay have:1. Girder Bridge’s structure characteristic, stress characteristic and the analysis method of structure mechanics is introduced in the essay. The finite element model studying of PC box-girder Bridge’s significance is illustrated according to the issues of the actual projects.2. The essay’s engineering background is 66m+120m+66m three-span continuous girder bridge in Zambia. And using the MIDAS/FEA builds the finite element model and analyses the spatial stress characteristic. The spatial stress characteristic is summarized according to models’ comparative analysis. The difference of the finite element model and beam element’s analysis and calculation results is listed.3. On the basis of the bridge model, the stress change of the bridge and the key section is analyzed according to change the bottom width and adjust the longitudinal prestressed reinforcement’s position. The influence of bottom width’s change and the reasonable bottom width are obtained.4. The transverse effect of Girder Bridge is analyzed caused by the longitudinal prestressed reinforcement, according to change the number and methods of the longitudinal prestressed reinforcement. The transverse effect caused by the longitudinal prestressed reinforcement is obtained, according to models’ comparative analysis.The spatial stress characteristic of Girder Bridge is understudied, according to the analysis above. The stress change under the action of load caused by the bottom width’s change and the more profitable section form are obtained. The transverse effect of Girder Bridge caused by the longitudinal prestressed reinforcement is obtained. Hope this research can be helpful to the similar bridges’ design in the future.