Temperature Effects on Horizontally Curved Concrete Box-Girder Bridges with Single-Column Piers

Abstract

Overturning failures of curved concrete box-girder bridges with single-column piers have occurred frequently in China in recent years. Lack of an appropriate design to resist the forces caused by unevenly distributed temperatures may be one of the main reasons for these failures. In design practice, only vertical temperature differences are accounted for in the design, and transverse temperature difference effects on curved bridges have been ignored. In order to achieve deeper understanding of temperature effects on curved concrete bridges with single-column piers, the authors studied solar radiation effects on a curved bridge, investigating the transverse and vertical temperature differences in the box girder using three-dimensional finite-element analysis. Then, the stresses and displacements of a curved bridge with different support arrangements were calculated and compared. The results show that the displacements and stresses caused by transverse temperature differences are comparable with those from vertical temperature differences in the curved box girder, which indicates that displacements and stresses are significantly underestimated by only considering vertical temperature differences for curved bridges. After comparing the stresses and displacements for different support layouts, it is concluded that the use of two pinned connected supports in the middle piers significantly reduces the vertical displacement by 46.2% under transverse temperature differences and by 55.6% under vertical temperature differences, whereas the thermal stresses do not vary with a change of support layouts.