Research on Optimal Design of Longitudinal Prestressed Reinforcement Layout for Long Span PC Beam Bridge

According to the principle and main factor of longitudinal prestress loss during the structure design at present,the long strand of the longitudinal prestress is changed into a short one in long span PC bridge.By this optimal design the friction loss would be reduced obviously in the stretching process and the prestress reserve in the root of the box girder would be enhanced during the cantilever construction stage.Meanwhile, with this method the stress state of the completed long span PC bridge can be improved and the shear capability in L/4 section can be strengthened effectively.It promotes a new design idea for long span PC bridge during the longitudinal prestress strand design.