Influence of Superstructure Pouring Concrete Volume Deviation on Bridge Performance: A Case Study

Due to factors such as casting, mold making, and construction errors, the actual size of the bridge structure will inevitably deviate from the designed size and dimension, and the amount of deviation between the two volumes is generally random and the location of the deviation is not fixed. However, this phenomenon that occurs in the actual practice has not been paid enough attention within existing studies. From a theoretical point of view, the apparent size of concrete will directly affect the cross-sectional stiffness, especially for statically indeterminate structures. This effect will be further reflected in the internal force and stress distribution of the structure. In addition, the variation of the poured volume of the bridge superstructure can also influence the dead-load effect of the bridge structure. Therefore, the influence of pouring concrete volume deviation (PCVD) on the cross-sectional stiffness of large-span continuous reinforced concrete rigid-frame (CRCR) bridges was first stressed and investigated in this paper. Field data of PCVD were monitored by measuring demolished sections with tools that ensure accuracy, and a sensitivity analysis was conducted to analyze the effect of PCVD on the cross-sectional stiffness at different locations. Statistical analysis of the measured data concluded that PCVD has a significant influence on the internal-force distribution and structural stiffness of the bridge, up to 30%. Finally, a theoretical method that considers the influence of PCVD was proposed based on the field monitoring data and the statistical analysis results.