| With the rapid development of China's transportation industry,bridge construction has achieved remarkable results.As one of the key links in bridge construction,steel bridge surface laying has always been the focus of attention at home and abroad.Because of its high temperature,fatigue resistance and high strength,epoxy asphalt concrete has been widely used in steel bridge paving.Scholars at home and abroad have carried out a lot of theoretical analysis on the laying of epoxy asphalt concrete bridge surface,but the research on epoxy asphalt concrete paving on the steel bridge surface of large vertical slope is relatively small,and the large slope paving structure is more likely to produce ruts,passage and other diseases.Therefore,the study of large-slope epoxy asphalt concrete steel bridge paving is of reference value for perfecting the design of epoxy asphalt bridge paving and promoting the development of steel bridge.Based on contact theory and thermal stress theory,this paper makes a systematic study on the surface laying structure of epoxy asphalt concrete bridge surface on a large vertical slope by using the finite element method:(1)Through the study of the mechanism and influencing factors of steel bridge paving disease,combined with the analysis of epoxy asphalt concrete and steel bridge paving characteristics,the four main mechanical control indicators of epoxy asphalt concrete bridge surface paving are put forward as: maximum pull stress,maximum shear stress,maximum vertical displacement and temperature stress.(2)Based on the contact theory,the study of the limited contact of wheel-large slope epoxy asphalt concrete steel bridge surface.The mode of slope at all levels is converted by the principle of time temperature equivalence,the load of slope at all levels is calculated by analyzing the force characteristics of the slope,the three-dimensional finite element model is established according to the conversion mode and load,and the mechanical control index is analyzed comprehensively for the different factors such as load,slope and speed.The maximum pull stress,maximum shear stress and vertical displacement are determined by different load settings.It is clear that the large slope increase has a significant effect on the two mechanical control indicators of maximum longitudinal pull stress and maximum longitudinal shear stress.The four mechanical indicators of maximum lateral pull stress,maximum longitudinal pull stress,maximum horizontal shear stress and maximum vertical displacement were determined to change significantly with the increase of velocity.(3)Based on the theory of thermal stress,the study of thermal stress finite elements in the laying of large vertical epoxy asphalt concrete steel bridge surfaces was carried out.A three-dimensional finite element model of thermal stress of large vertical epoxy asphalt concrete pavement structure was established,and the thermal conduction at the surface temperature of the paving layer at 50 degrees Celsius and the steel bridge panel temperature of 20 degrees Celsius was analyzed,and the temperature distribution after thermal conduction showed a step-by-step uniform decrease.On the basis of thermal conduction,the thermal stress research of 20 degrees Celsius and 30 degrees Celsius was carried out,and the results showed that the heating had a significant effect on the maximum lateral pull stress,and the maximum lateral pull stress at 20 degrees Celsius and 30 degrees Celsius,respectively,with a significant effect.Finally,the thermal stress under load is studied,and the result surface: thermal stress under the same load,temperature change has a significant effect on the maximum lateral pull stress and the maximum longitudinal pull stress. |
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