Analysis Of Temperature Effect Of Steel Deck Of Nanjing Yangtze River Bridge Under High Temperature Pouring And Pavement

The pouring asphalt concrete is widely used in long-span steel box girder,and the cutting temperature of pouring asphalt concrete is as high as 220 ? ? 240 ?.Due to the anisotropic characteristics of steel deck,such high temperature pouring on the steel deck will lead to uneven temperature distribution in the steel beam,resulting in the temperature effect in the steel beam that can not be ignored.In this paper,the influence of pouring asphalt concrete on thetemperature field of steel bridge and the resulting temperature effect are studied.The finite element software ABAQUS is used to simulate the temperature field and temperature stress.The research contents are as follows:(1)The transient heat conduction theory is used to determine the thermal boundary conditions and the thermal parameters of steel and asphalt mixture for the simulation of temperature field.Secondly,the heat transfer between asphalt mixture and steel bridge surface is simulated by setting the interface heat transfer coefficient.(2)Through the comparison between the measured value and the simulated value,the parameters selected in the finite element simulation can effectively simulate the actual environment.(3)Through the sensitivity analysis under different working conditions during the construction of pouring asphalt concrete,it is found that the greatest influence on the temperature field is the thickness of the pavement layer,the cutting temperature and the heat transfer coefficient of the interface,and the degree of influence is determined.Secondly,the influence of different seasons,paving time and wind speed on temperature field is limited.Thus,the most unfavorable conditions of asphalt paving are determined.(4)The opening and multi rib of Nanjing Yangtze River bridge deck are supported by the dense longitudinal beam and the steel anti pulling support under the cross beam.The difference between the overall structure and the traditional steel box girder will cause the internal temperature effect to change.In this paper,the life and death element method is used to simulate the paving process to obtain the temperature field change of the steel bridge,and the sequential thermal coupling method is used to calculate the temperature effect to determine the overall mechanical response of the steel beam and each component under the temperature effect.(5)Through the influence of the transient temperature field on the steel deck,the vertical displacement of the paving area of the steel deck is obtained,and the difference of the paving thickness in the paving process is simulated.