Analysis of Spatial Mechanical Behavior of Pylon and Girder Temporary Fixity Structures of PC Cable-Stayed Bridges

The restless increase of the span length and main girder width of prestressed concrete(PC) cable-stayed bridges exhibits the more and more significant spatial effect of the bridges.In the process of cantilever construction of the main girders of the bridges,the commonly-used method of pylon and girder temporary fixity often results in cracks in the vicinity of Segments No.0 of the girders.The structural analysis software MIDAS/Civil is used herewith to simulate and analyze the construction of the spatial structures of the cable-stayed bridges used with the temporary fixity.The results of the simulation and analysis show that it is the spatial effect of the temporary fixity that causes the cracks in the girders and the corresponding proposal for setting the temporary fixity structures is made.