Mechanical Properties Study On The Top Flange And Diaphragms Of Long Cantilever Box Girder Bridge

In recent years, with the construction of road and urban transportation development,long cantilever single-box multi-room wide box section was used in a large number ofprestressed concrete continuous girder bridge to reduce the weight of the upper part andconstruct quickly and conveniently. In this article, a FEM model of a long cantilever boxgirder bridge was established by ANSYS to study the transverse stress distribution of topflange and analyze the force characteristics of cross diaphragms, the topologyoptimization method was used to establish the strut-and-tie models of cross diaphragms tosimplify the analysis and calculation. The main work of the paper is as follows:1. A transverse frame model of box girder was established to study the transverseprestressing forces effect of different box girder size parameters.2. Analysis different tendon linear and different top flange thickness to study thecharacteristics of the transverse stress of the top flange, and some suggestion was gave forthe crack of box girder top flange.3. Revealed the force characteristics of cross diaphragms under different loadconditions, and put forward a simplified calculating method for cross diaphragms.4. Using topology optimization method established strut-and-tie models for crossdiaphragms under different load combinations as the simplified calculation model. In theend, a brief introduction was made to show the method of reinforcement of strut-and-tiemodels.The results of this study suggest that a moderate increase in the thickness of the topflange and curve linear tendon can effectively adjust transverse stress of the top flange.And the fulcrum and web position is the main control node according to the diaphragmsstrut-and-tie models created by the topology optimization single-box multi-roomcantilever wide box section.