Abstract:Relying on the four-column prestressed bent cap structure of a viaduct under construction in Yuyao City, Zhejiang Province, the numerical simulation is used to analyze the evolutionary mechanism of bridge mechanics and law of damage expansion under the influence of different side column spacing conditions. The corresponding treatment measures are proposed to be applied in the actual construction. The results of the study show that (1) the rebar stresses of bent cap increases gradually with the increase of the side column spacing L. When the spacing reaches L=23.9 m, the upper midspan and the lower two sides of the longitudinal rebar are close to the failure strength. The safety of bent cap structure should be considered. (2) The concrete tensile zone is mainly concentrated in the bent cap, but with the gradual increase of the side column spacing L, the tensile zone is gradually transferred from the bent cap to the top zone of the side column. When the side column spacing L＞18.4 m, the structural damage of the side column is serious, and the bearing capacity is greatly reduced. (3) When the side column spacing is too large to affect the safety of the bridge, it is proposed to replace the rigid connection between the bent cap and the side columns with a flexible hinge bearing in order to reduce the effect of its force transfer.
