Analysis Of The Cause Of Crack In Concrete Box Girder Of Baishazhou Bridge And Research Of Remedial Measures

Concrete box girder cracks very easily because of the role of various loads, and the shrinkage and creep of the concrete itself. Without being handled timely or properly, crack maybe further extend to endanger the safety of box girder, and affect the life span of the bridge. Therefore, the detection and treatment of the cracks plays an important role in detection and reinforcement of a bridge.This paper mainly focus on cracks in the concrete box girder of Wuhan Baishazhou Bridge. First, the report of cracks detection in Baishazhou Bridge is reviewed, after which the distribution of crack is analysised. Then, we construct the CAE modle of concrete box girder in the finite element software ANSYS, and solve the first principal stress field of concrete box girder under various load, which is for later analysis. The influence of the weight of the bridge, wind, temperature, vehicles, and non-uniform settlement are taken into account in the finite element analysis. The results for the case that the tension stress of the cable-stayed losses, as well as the local stress field near the wheel when vehicles running on the bridge are analysised, in which the effects of the weight of the bridge and the role of vehicles are to be considered. The bridge temperature gradient mode in China's current code is mainly used when the temperature factor is to be considered. Based on the distribution of crack and the results of finite element analysis, it is found that the main causes of the distribution of crack in the concrete box girder. The remedial measures of crack, the local reinforcement methods of box girder, as well as the related bridge care proposal are given out according to the inherent causes of cracks and its status. At the same time, it is validated that the local force is improved after pasting plate on the box girder.