Study On Coupled Dynamic Behavior Of Temperature And Load Of Steel Bridge Deck Pavement In Chongqing Area

In recent years,with the rapid increase of traffic volume and the frequent action of harsh natural environment,as well as some defects in design and construction,cracks,upheaval and other diseases occur in the deck pavement of many bridges,especially steel deck pavement.Because the steel bridge deck pavement is significantly affected by complex and changeable weather conditions and heavy traffic,domestic and foreign experts have made certain achievements in the design theory and methods of long-span steel bridge deck pavement,and have accumulated some experience in pavement materials,design control indicators and other aspects.However,the research on steel bridge deck pavement technology mainly focuses on the pavement structure and materials,while the research on the mechanical response of the pavement structure under the combined action of traffic load and temperature is relatively small.In view of this,the early damage phenomenon of steel bridge deck pavement structure layer is effectively solved,and the stress situation of asphalt pavement layer under the combined action of moving load and temperature is more accurately fitted.ANSYS software is used to calculate and analyze the steel bridge deck pavement structure layer.The research contents are as follows:1.Investigate the diseases of bridge deck pavement structural layers of several bridges in Chongqing area,and analyze the causes of typical diseases such as cracks,deformation and structural layers in different pavement structures based on the climate and traffic environment in the area.2.Using ANSYS software to establish a local beam segment model,comparing the temperature in different seasons,the position of bridge deck and the type of pavement structure,calculating and analyzing the influence of natural environment temperature Periodicity changes on steel bridge deck pavement structure layer,finding that the internal temperature stress of high temperature pavement layer in summer is mainly compressive stress,and there is an interactive transformation between tensile stress and compressive stress,while the surface of pavement layer is tensile stress in winter at low temperature.3.In the dynamic finite element analysis process of moving load,the moving load is applied to three different positions of the center of the stiffening rib,the welding place of the stiffening rib and the center of the web plate of the bridge deck to determine the most unfavorable load position of the pavement structure layer.Then,the dynamic responses of the pavement structure to vehicle speed,Damping ratio,overload andReducer brake are analyzed.It is found that vehicle speed and Damping ratio have no significant influence on the mechanical indexes of the structure.Overload has the greatest influence on the vertical displacement of the structural layer.Reducer braking has the most significant effect on the maximum shear stress between layers.4.Considering the influence of superposition effect of driving load and temperature load on pavement structure layer,the coupling effect of low temperature and heavy load and the coupling effect of high temperature and Reducer brake are selected.Through comparative analysis of double-layer SMA,SMA+GA and double-layer EA pavement structures,it is concluded that under the coupling effect of low temperature and heavy load,the mechanical control indexes of SMA+GA pavement structure are relatively balanced.Under the coupling effect of high temperature and Reducer braking,the double-layer EA pavement structure has excellent resistance to vertical deformation and shear failure.To sum up,considering the humid and hot climate environment and heavy traffic conditions,the double-layer EA pavement structure with better high temperature performance should be selected for the design of steel bridge deck pavement structure.