Analysis of temperature stress for concrete box girders cracking

Use 3D solid finite elements, distribution rules of temperature-induced stresses in concrete box girders are investigated. The thermal gradient actions and the variation of some critical parameters are analyzed, such as the stiffness ratio of the rib to top slab, and the ratio of side-to-middle span. At the same time, the thermal gradient effects are compared according to the design specification of JTJ 021-89 and the updated version of JTG D60-2004. The results of analysis show that there exist high transverse tensile stresses on the top slab and high longitudinal tensile stresses on the top and bottom slab. By comparing the theoretical results at the potential locations of maximum tensile stresses to the practical cracks investigated in the same project, the influence of temperature stress are discussed in the bridges of concrete box girder.