Mechanical Behaviors Of Prestressed Concrete Box-Girder Bridge

With the enhancement of our national strength and improvement of the national economy, the transportation has gotten considerable progress. Bridges are the hinges of transportation, which plays an important role in transportation lines. As the development of the bridge design and construction, the long-span bridges have been widely applied. Some large-scale bridges occurred serious consequences because of static and dynamic behaviors, thus the analysis of static and dynamic behaviors are indispensable to these large-scale bridges. The temperature stress can reach the magnitude of stress produced by the vehicle loads for the large scale bridges, which plays a major role in bridge crack, so the effects of temperature on the large scale bridge can not be ignored.In this paper, based on one prestressed concrete continuous box girder bridge, the 3-D finite model was established by adapting the finite element software ABAQUS. Then the mechanical behaviors of the box girder bridge under the self-weight, the live load on bridge, the temperature effects and the moving load were studied. The main conclusions can be drawn as follow.(1) The prestressed characteristic analysis was conducted on the box girder bridge by adapting the simulation model of the box girder established by the finite element software ABAQUS, and the results shows that the change and distribution of stress are in agreement with the theoretical and experimental results.(2) Under the self-weight, the distributed load and the concentrated load on bridge deck, the mechanical characteristics, stress and displacement changes of the box girder bridge were analyzed and calculated, and the results shows the self-weight plays a prominent role in the static analysis of bridge.(3) The temperature stress and the displacement distribution of the box girder bridge under the seasonal and sunshine temperature difference were analyzed. And the temperature stress and the displacement distribution obtained by adapting the temperature gradient of China, New Zealand, France and British are contrasted. The maximum displacement obtained by China, France and British standards are close, and New Zealand standard is intend to be more safety. The maximum tensile stress obtained by China, New Zealand and France standards exceeds the design value, and there is no tensile stress according to British standard. Under the seasonal temperature difference, the deck of concrete bridge is suffer from the maximum tensile stress, so the special attentions should be paid on the bridge duck in the operation of the bridge.(4) The distribution of displacement and stress for the prestressed box girder bridge under the moving load were studied by using the finite element software ABAQUS to transfer the Dload in Fortran.