Temperature Effect Of Continuous Prestressed Concrete Beam Bridge

Because of the bad heat conduction of the concrete material, prestressed concrete bridges are subject to varied of temperature actions, which can make notable influence on the transformation and stress of bridge structures, especially the long-span bridges. Since 1950s, amount of experiments and research work have been carried out to study the influence brought by temperature actions. In recent years, a series of new problems are noticed in both the bridge construction and service period, which arouses more and more interest and attention of civil engineers in different countries.After consulting lots of professional theories and academic articles, the influence of temperature actions to the prestressed concrete continuous bridges is researched in this paper. All the following analysis is on the basis of a three-span continuous bridge whose main span is 120m. Firstly, according to the thermal conduction theory and finite element method, the model of zero-block, which considers the 3rd-type thermal boundary conditions, is built to analyze the effect of cementitious hydration heat. The unsteady-state thermal solution is done to conclude the rules of temperature development for this structure and to predict the temperature distribution under field conditions. Then some measures are commended to control the structural temperature and ensure the quality of the casting concrete. Secondly, using the existing computer program ANSYS, the model of determinate T-shape bridge structure is developed to study the influence of the solar temperature action on it. According to the thermal conduction theory, the steady-state thermal solution is done to analyze the temperature distribution in the bridge structure under solar radiation. On the basis of the thermal solution result, the structure analysis is done to study the feature of bridge transformation and stress, which is useful to make active modification to the erection elevation for different beam segments and helpful to optimize design for the structure details. Finally, the whole bridge structure is modeled, which considers many temperature gradients of different national bridge specifications. Using finite element method, the structure analysis is done to compare the influence of different...