Dynamic Response Of Low Embankment And Asphalt Pavement Under Heavy Load Dynamic Load

With the increasing shortage of land resource,more and more low embankments are used in the design of highways.In the port cities,the roads of low embankment are affected by the dynamic load of the heavy load vehicle and the soft foundation,which lead to the serious damage of the roadway of the low embankment.Therefore,it is necessary to systematically study the dynamical response laws of roadbed and asphalt pavement,which generated by the heavy vehicles travelling on low embankments.And many road diseases can be prevented.In this paper,firstly,according to the flatness condition of asphalt pavement,the relationship between the standard deviation of different flatness and the waveform parameters is calculated.And the relationship between wavelength,amplitude and flatness standard deviation is analyzed by MATLAB software,and it applied a quarter-vehicle vibration model having two degrees of freedom to analyze the influence law of wavelength,amplitude,vehicle speed and axle load.The result shows that the dynamic load coefficient can reach 1.45 under adverse conditions.Then,ABAQUS software was used to establish the three-dimensional pavement structure model,and the influence of speed and axle load on dynamic response of pavement structure was analyzed.Based on the finite element simulation and experiments,the dynamic response of the low embankment under different loads and different speeds was analyzed by means of the expressway engineering of the west outer ring low embankment section of Tianjin Binhai New Area.The results show that the stress,strain and displacement of the pavement structure are larger than those of the static load under the action of the sinusoidal load.With the increase of axle load,the dynamic response of pavement and soft soil embankment structure is linearly increased.With the increase of speed,the vertical stress of the pavement structure is gradually smaller and the vertical displacement increases first and then decreases.The additional vertical stress of the soft soil embankment increases and the growth rate is getting slower and slower.Therefore,when the roads are designed with low embankment in the soft soil area,the influences of axle load and speed on asphalt pavement and roadbed should be fully considered.