Analysis On Temperature Field Simulation And Temperature Effects Of Large-span Continuous Rigid Frame Bridges

Large-span continuous rigid frame bridges in the project are widely used in recent years.Due to different thermal conductivity of concrete material, the temperature change inside theconcrete structural component obviously lags behind that of outside caused by temperaturedifference between one side and another side of box-girder, therefore, the non-uniformdistribution of temperature field and thermal stress is formed inside of the structure. Becausethe temperature stress under different temperature gradient mode is quite different, meanwhile,the temperature stress decreases the crack resistance of concrete and affects both the structuralintegrity and durability,so, getting the suitable temperature gradient mode of large-spancontinuous rigid frame bridge in a region and studying the effect of temperature under thetemperature loads through the field measurement and theoretical calculation is very necessary.Hongwuwo super span bridge (prestressed concrete continuous rigid frame bridge) ischosen as the background, adopting the testing method of "time-temperature-strain"synchronization system, the temperature field and the effect of box girder is analyzed, in orderto get temperature gradient curve obtained for this region, the load mode of the temperature isfitted respectively specified in the road bridge design specifications railway bridge designspecifications according to the measured data. In this paper, the finite element softwareANSYS is used in the analysis of the box girder transient temperature field simulation, themeasured values are compared to verify the accuracy of the simulation analysis. Beamsegment solid model is created to get the temperature and stress distribution discipline insidethe box-girder under the loads of positive and negative temperature difference, thetemperature stress of concrete box-girder under sudden drop in temperature is researched andthe box girder structure size and cooling rate effects of the box girder temperature stress isobtained. Through the temperature field calculation results under sudden drop mode intemperature, the nonlinear analysis of the top and bottom plates in the box-girder is conducted,by simulating the development and distribution of the crack under sudden drop in temperature,the location of temperature cracks prone to appear in the continuous rigid frame bridges isanalyzed. Simultaneously, the impact of stress and deformation in the rigid frame bridgeunder the loads of temperature difference is researched by using the finite element softwareMidas Civil.