The Shrinkage And Creep Analysis Of PC Concrete Box Girder Bridge

At present, quite a bit of cracks appear in long-spanned prestressed concrete bridge with box girder during the process of construction or operations, which is more seriously in webs. In many reasons of causing cracks, only a few studies are reported about the influence of concrete shrinkage and creep on cracks for its computational complexity. If any, most calculations are only based on the two-dimensioned finite element model. So it's significant that how to analyze the spatial effect of concrete shrinkage and creep by utilizing large software.This paper based on the program of transportation developments in west --"the research on cause and treatment technology of the contentious box girder bridge and continuous rigid frame box girder bridge", which program take on by ministry of communications highway research institution and participated by the Changsha University of Science and Technology, on the background the Dongying Yellow River long-span bridge in Shandong province. The whole 2-D model was established applied the Finite Element Analysis program and the effect by the shrinkage and creep of the concrete was considered, the rule of the contentious girder bridge and continuous rigid frame bridge effect by the concrete shrinkage and creep when it was used sumed up, the author bring forward a new fold measure to reduce the concrete shrinkage and creep when the bridge working.This paper make use of the software ANSYS which offered by the APDL to set up the local model of the girder beam model, and is applied the creep of the program to carry on the calculation of concrete shrinkage and creep of the girder beam model. On the base of the calculating results, the stress in the box girder webs and the stress loss in the vertical pre-stressed steel bar were researched. The rule of box girder webs stress and the vertical pre-stressed was effected by the concrete shrinkage and creep when it was working. The vertical pre-stressed loss was also calculated the concrete shrinkage and concrete creep according to the current standard, and the contrast was made between the calculating result from ANSYS. The suggestion was put forward to calculate the using standard formula.