Study on the Effect of Uniform Corrosion on the Durability of Corrugated Web-Concrete Combination Box Girders with Steel Base Plate

In order to study the effect of uniform corrosion on the durability of steel bottom plate corrugated web-concrete composite box girder, this new type of steel-concrete composite structural girder bridge is analysed by using the time-varying reliability as the durability index. The static loading test is carried out on the steel bottom plate corrugated web-concrete composite box girder before and after corrosion, the mid-span deflection and stress before and after corrosion are calculated, and the time-varying reliability is used to calculate the reliability index of the composite box girder. The results show that under static loading, the mid-span deflection of the model test beam increases with the increase of load. The stress values before and after corrosion do not differ much when the load is small, and there is a significant difference in the stress values of the steel bottom plate with the increasing load. According to the relevant codes and using the primary second-order method of moments, the time-varying reliability indexes under different t moments are calculated by Matlab software.