Study On Coupling Effect Of Temperature And Atmospheric Wind In Long Span Continuous Rigid Frame Bridge With Super High Pier

The overall stiffness of the super-high pier long-span continuous rigid frame bridge is smaller than that of the small span similar bridge type,and the structure is more flexible.It has a higher sensitivity to many loads during its construction.In the actual monitoring,it was found that the temperature load and the wind load and the coupling effects of the two have a non-negligible impact on the linearity and stability of the structure during the entire process of bridge construction.The following studies have been carried out for this purpose:1.Based on the monitoring data of the actual project,the maximum temperature difference between the inner side and the back side of the wall thickness of the pier was determined.A non-linear temperature difference curve along the wall thickness direction was fitted and established using nonlinear regression analysis:T_x=25.7+4.1e^-5.25x.According to this formula,the solar thermal load was loaded into the ANSYS solid model for thermal coupling and structural analysis,and the maximum pier offset was calculated to be 5.5 cm.The influence of the axis misalignment of the pier on the linear and stress of the upper main beam is calculated and analyzed.2.According to the conservative wind-bridge specifications of highway bridges,the deformation analysis under different wind load conditions was carried out in different construction stages of the structure.It was found that with the increase of wind speed,the deformation of the structure increased exponentially;3.The non-linear solar radiation temperature effect,the wind-induced static wind effect,and the temperature-static wind during the entire construction process of the highest bare pier stage of the high-rise pier long-span continuous rigid frame bridge,the maximum double cantilever of the main beam,and the completion stage After the analysis of the coupling effect.The finite element software ANSYS was used to analyze the geometric nonlinear stability of the structure under the above three conditions.4.According to the calculation results,the influence of temperature and static wind and temperature-static wind coupling effect on the structural stability in different construction phases is obtained.It is found that temperature and static wind load will reduce the structural stability,but The effect of coupling on the structural stability affects the static wind load,and the increase of wind speed can improve the temperature effect of the structure.5.For the bridge piers and cantilever cantilever construction,the stability of the bridge and the main beam under the coupling of temperature-aerostatic stability decreased significantly.Three kinds of temporary control measures to improve the stability of the structure were proposed,and the control effects of each measure were compared and analyzed.The results show that the construction of the main piers during the construction phase with temporary lateral linkages and the provision of temporary longitudinal overgirders in the main girder during the construction of the long cantilever can significantly increase the structural stability.