Stiffness Strengthening Analysis of Railway Bridges with Low-Height Reinforced Concrete Beams

The low-height reinforced concrete beams of Hefei-Jiujiang Railway with span 8.0 m are often faced with the problems such as the middle-span deflection exceeds the limit and the vertical rigidity is insufficient,which will impact on the speedup of the railway.In order to improve the vertical rigidity of this kind of bridges,the proposal of pasting steel plates and exerting external prestress was suggested to be adopted.The change of deflection and frequency resulting from the strengthening was studied by FEM analysis and measured data.The research provided a full assessment of stiffness strengthening effect about this two methods,and it provides reference for the stiffness strengthening project about low-height reinforced concrete beams of the same kind.