Research On Temperature Effects And Shrinkage-creep Analysis For Long-span Continuous Rigid Frame Bridges

Recently, based on the economic development of our country, many long span prestressed concrete continuous rigid frame bridges are built.Temperature effects and Shrinkage-Creep have an important influence on this kind of bridge's design and application. The massive results on this field have been obtained, however, there are few study about the real bridge.Based on the measurement of temperature distribution field of Longtanhe bridge due to solar radiation, we obtain the fitting curve of vertical temperature difference distribution of box girders and lognitudinal temperature difference distribution of hollow pier.Applying the soft of ANSYS, the paper analyzed the bridge using measured temperature gradient or temperature gradient according to General Code for Design of Highway Bridge and Culvert.When the continuous rigid frame bridge's actual closure temperature is higher than the design closure temperature, the closure temperature's difference will cause horizontal displacement at top of pier, and cause the structure to have the temperature intennal force. A horizontal jacking force is exerted to eliminate the adverse effect of closure temperature's difference. Two calculating methods of jacking force are proposed in this paper:eliminating the horizontal displacement at top of pier method and eliminating the tensile force in main girder method. Taking the Longtan River Bridge as a practice example, the high closure temperature's horizontal jacking force is calculated according to the above two methods separately in this paper. Through analysis and comparison, both results are basically consistent.It's showed that two calculating methods are feasible, and eliminating the tensile force in main girder method is simpler and quicker.The paper adopted the software of Bridge Doctor to analysis the influence of shrinkage and creep on the deflection and stress of bridge and obtained some conclusions.