Deflection calculation of Long-span Prestressed Concrete Box-girder Bridge with shear effects

The long-term deflection is a common phenomenon of Long-span Prestressed Concrete Box-girder Bridge (LPCBB). And there are still many ambiguous reasons as to the cause of the deflection of LPCBB. Based on the basic mechanics formula, factor influencing shearing deformation of cantilever beam was obtained. The difference of shearing deformation between beam with rectangular section and beam with box-girder section was obviously indicated. Then a finite element model simulating the cantilever construction process for the North Bridge of Nanjing Second Yangtze River Bridge was conducted to investigate the influence of shearing deformation to camber. The analytical results show that there are cumulative errors of 25.38 mm for midspan if shearing deformation is ignored. It is likely that shearing deformation and consequent creep are can´t ignore for LPCBB.