Rutting Analysis And Prevention Of Bus Station Asphalt Pavement

With the continuous increase in the number of private cars in China,traffic congestion has become one of the urban diseases that plague the city.In order to solve the congestion problem in urban development,the bus priority strategy came into being.As one of the important components of this strategy,bus travel is popular among the general public for its convenience,economy and affordability.Many cities have tailored bus lanes for bus operations,and bus stops have become an important hub for public transport.However,in the actual operation of the road,the asphalt pavement near the bus stop is often prone to serious road surface damage,especially the rut damage.The rut damage on the road near the bus stop will not only have a greater impact on the smoothness of the road,In severe cases,it may even pose a threat to the safe operation of the bus.Its characteristics of water accumulation in rainy days may seriously affect people’s travel experience.According to the mechanism of road rutting disease,combined with the geometric and mechanical model of the bus during operation,the rutting prediction model is established according to the pavement structure commonly used in the design of urban main roads in Changsha.According to various influencing factors in the process of pavement use,the causes and deterioration rules of the rut disease of asphalt pavement at bus stop are analyzed.Because the rutting disease is related to the temperature state of the asphalt pavement,according to the change of the daily average temperature of the high temperature season in Changsha and the thermophysical properties of the structural layers of the pavement,the pavement temperature field model is established to analyze the temperature distribution and difference inside the asphalt pavement.It is concluded that the internal temperature of the pavement structure changes gradually with temperature,and the temperature of the surface layer structure is generally higher.According to the mechanical characteristics of each structural layer of the pavement,the distribution of mechanical response inside the structural layers of the pavement under the axle load of the bus is analyzed.It can be concluded that the upper layer of SMA-13 is subjected to the highest load level,and the internal stress of each structural layer of the pavement is gradually reduced as the depth deepens.According to the viscoelastic physical parameters of the asphalt surface layer,combined with the research results of the pavement temperature field,the vertical displacement generated by the road surface under different axle loads of the bus is analyzed in detail.And establish the relationship between the depth of development of the rut and the number of axle load.Combined with the distribution of stress in the pavement structure layer,the causes of the rutting of asphalt pavement at the bus stop are discussed.Finally,it is determined that the vertical deformation of the mid-layer asphalt surface in the pavement is one of the important causes of the rutting disease.Combined with the simulation results of the asphalt pavement rutting,the solution to the prevention of the rut on the asphalt pavement of the bus stop is proposed.The rutting simulation was carried out for different prevention methods to evaluate the effectiveness of the prevention method.The results show that the method of base layer reinforcement can not effectively prevent the occurrence and deterioration of rutting diseases;while the improvement of surface strength and high temperature stability can delay the deterioration of rutting,and paving the road with high-performance materials,especially the mid-layer structure,can prevent the occurrence of rutting diseases to the utmost extent.