Stability Evaluation Of Bridge Deck Pavement Of Highway Steel Bridge In Cold Region Of North China

As the direct bearing of vehicle load,the deck pavement has the functions of dispersing load,protecting bridge structure and preventing structural corrosion.Once damaged,it may directly block the traffic and endanger the durability and safety of the bridge.At present,the design of asphalt concrete pavement is mainly used to refer to the conventional practice of asphalt mixture,and the influence of extreme temperature and traffic vibration load is not considered.At present,the design of asphalt concrete pavement is mainly used to refer to the conventional practice of asphalt mixture,and the influence of extreme temperature and traffic vibration load is not considered.In view of this,the project relies on the Rear-lilac Bridge in Shenyang,Liaoning province,with the use of field monitoring,theoretical analysis,numerical simulation and laboratory experiment.And monitor the site temperature of the asphalt concrete pavement in the cold region.Then the author analyzes the mechanical response characteristics of asphalt pavement under heavy traffic load and fatigue property of asphalt concrete pavement.The main research contents and achievements are as follows:(1)In this project,the temperature sensor is embedded in the asphalt concrete pavement of the rear bridge on the rear bridge,and the temperature of bridge deck pavement in summer,autumn and winter is monitored.The field monitoring data show that the upper temperature of the same position in different layers is higher than that of the lower layer.At high temperature in summer,the temperature of the 3 bridge and the No.4 bridge is above 47 degrees C,the temperature of the SMA layer is above 43 C,and the temperature of the GA layer is above 40.On this basis,the prediction formula for high temperature and low temperature of steel bridge deck pavement in cold region of North China is put forward.(2)The coupling effect of automobile tires and steel bridges is considered,and the finite element model of the whole bridge is established under the vehicle load.The mechanical response characteristics of steel bridge deck pavement under static,dynamic and temperature effects were studied.The numerical simulation results show that under the tire load,the maximum values of tensile stress and shear stress of RA05 layer and SMA 13 layer are all located in the longitudinal U rib edge position of two wheel group load symmetry,and the tensile stress and shear stress of RA05 layer are all larger than those of SMA 13 layer.(3)RA05 concrete and SMA 13 concrete,RA combination system under different strain bending fatigue test shows that the pavement materials with the increase of bending tensile strain,initial bending stiffness modulus decreases,and phase Angle increases,the unit dissipation decreases;The fatigue life of the material has a good correlation with strain and accumlative dissipation,and the fatigue life of the material decreases with the increase of strain and accumulative dissipation energy.Shear fatigue life and interlayer shear stress are double logarithmic linear relationship.With the increase of shear stress,shear fatigue life decreases.Through the above research,this paper puts forward the dynamic stability evaluation index of asphalt pavement in cold area,for pavement structure design,and provide a theoretical basis for the design of material,to ensure the long-term cooperative work and pavement performance,thereby reducing the early damage of asphalt concrete pavement in cold area in China.