Study On The Influence Of Multi-span Continuous Beam Bridge System Transformation On Structural Effect

Cantilever casting method is the preferred method for the construction of long-span prestressed concrete continuous beam bridges due to its features such as no need to set up a landing bracket,good continuity of the beam reinforcement,and good integrity of the concrete.System transformation is an important construction stage for the completion of the structure from the cantilever T to the closure of the whole bridge.The order of system transformation will have a significant impact on the stress and deflection of the main girder during construction and after completion of the bridge.Meanwhile,temporary consolidation is not only an important measure to ensure the safety and stability of the structure during the cantilever construction,but also an important part of the system transformation process.Therefore,based on practical engineering,this paper studies the advantages and disadvantages of different simulation methods of temporary consolidation and the influence of different system conversion sequence on the main girder.The main research contents are as follows:(1)Several common forms of temporary consolidation and their advantages and disadvantages are introduced.Based on the practical project,the results of different temporary consolidation simulation methods on the internal force and deflection of the main beam are studied,and the limitations and application scope of various methods are analyzed.(2)By setting different temporary consolidation parameters,the differences of temporary abutment spacing,on the stress and deflection of the main girder during the construction process and after the completion of the whole bridge were studied to provide a reasonable design range of temporary consolidation parameters.(3)Under the specific closure sequence and under the different system conversion sequence,the differences of stress and deflection of the main girder during the construction process and after the completion of the bridge are studied.Considering the safety of the bridge during the construction process and the ideal alignment of the bridge after the completion of the bridge,a reference is provided for the reasonable system conversion sequence in the project.(4)Under the specific system conversion order,the influence law of different demolition order of temporary abutment on the reaction force of permanent abutment and temporary abutment and the deflection of cantilever end under different temporary abutment spacing is studied,which provides a reference for the reasonable demolition order of temporary abutment in practical engineering。...