| Prestressed concrete-steel trough girder composite continuous beam bridge is a new kind of bridge system.The new bridge system is based on the hybrid girder bridge,in the mid-span,the steel beam optimized for concrete-steel trough girder composite beam structure.It not only has the advantage of the hybrid girder bridge,in addition,the problem of steel box girder bridge deck pavement easily damaged have been solved,because of the combination of steel trough girder and deck in the mid-span.This paper reviewed the relevant literature and research results at home and abroad.Draw lessons from some advanced design information and taken the long bridge and great bridge as the engineering background.Reference Hankou side bridge approach structure of Erqi Yangtze River Bridge and redesign it,thus the steel box girder replaced by concrete-steel trough girder composite beam structure.The main contents are as follows:Firstly,this paper describes the composition of cross section and calculation principles of concrete-steel trough girder composite beam structure.The mechanics action,structure form and structure type of the steel-concrete composite segment of the bridge have been discussed.Besides the construction features,mechanical properties and performance of a variety of connectors also have been discussed.This is the theoretical basis for the calculation of the full-bridge design.Based on the long-span bridge,reference Hankou side bridge approach structure of Erqi Yangtze River Bridge,the prestressed concrete-steel trough girder composite continuous beam bridge have been redesigned and determined the specific size of the cross section of composite beam.Secondly,based on finite element analysis software Midas Civil,the full bridge model is established,the overall design of the composite segment of the bridge is studied.Structural stress and displacement are parametrically analyzed by the proportion of the length of composite beam out of the main span(k).It is clear that the evaluation criteria of bridge span optimization mainly include the bearing of side pier shall not appear tension,the bending moment of the joint is as small as possible and the displacement of the structure induced by internal force should be reduced as far as possible.In this way,the reasonable value of k is determined.The mechanics performance and deformation of bridge at each construction stages are analyzed.Analysis of bridge under individual loads and their combinations during operational phase are also conducted.Finally,the mechanics performance of the steel-concrete composite segment is studied,the local model of which was established by Ansys.The distributions of the longitudinal,transverse,vertical stress and main stress of the steel-concrete composite segment under the most unfavorable load are calculated. |
