| The water film is formed when the rainwater is difficult to discharge on rainy days and it is to drain the water when the vehicle at high speed passes through the water film,which is called tire hydroplaning.This may lead to traffic accidents.The still water film becomes dynamic water flow and the instantaneously hydrodynamic pressure is formed when the high-speed tire drives over the stationary water film.This may lead to water damage of asphalt pavement.Thus the study of the flow characteristics of water flow and the distribution of hydrodynamic pressure have great significance for reducing the phenomenon of tire water skiing and analyzing the water damage mechanism of asphalt pavement.This paper establishes a tire-water film-asphalt pavement model based on porous media theory and fluid mechanics theory.And the water film holding force of the tire and the dynamic water pressure of the asphalt pavement are analyzed from three aspects of water film thickness,driving speed and road type.Firstly,this paper describes the formation mechanism of asphalt water film in rainy days.The reasons for the formation of water film of asphalt pavement and the influence of factors such as drainage length,road gradient,rainfall intensity and road structure depth on water film thickness were investigated.In this paper,a theoretical analysis model of water film thickness is established based on the empirical model of water film thickness at home and abroad.Secondly,three-dimensional asphalt pavement was constructed by two methods,which are based on BA scale-free networks,the theory of quartet structure generation set and CT scanning technology.The reliability and stability evaluation of random growth pavement models are evaluated by two indexes of permeability coefficient and gradation curve.Then the radial tire model was built by AutoCAD and finite element software,and the tire model was inflated and statically loaded.The reliability of the tire model was verified by comparing the calculation of the sinking amount with the experimental data.The repaired tire mesh and the above-mentioned three-dimensional asphalt pavement mesh are introduced into the software simulation work area,and the water flow basin is established according to the Mie Gruneisen equation to establish a tire-water filmasphalt road model.Finally,the effects of water film thickness,driving speed and road type on the water film lifting force of the tire and the hydrodynamic pressure of the asphalt pavement are analyzed.The lifting force of the water film of the tire increases with the thickness of the water film.When the thickness of the water film exceeds the depth of the longitudinal groove of the tire,the lifting force of the water film increases sharply.The lifting force of the tire is gradually increased as the speed of the wheel increases.The peak value of the hydrodynamic pressure of the asphalt pavement increases with the increase of the driving speed,and the higher the speed,the shorter the hydrodynamic pressure reaches the peak from 0,that is,the shorter the periodicity of the hydrodynamic pressure.When the working conditions are the same,the AC pavement are subjected to the maximum lifting force,the SMA pavement are secondarily stressed,and the OGFC pavement are subjected to the minimum water lifting force.The OGFC pavement has the lowest value of the tire lifting force or the water pressure in the pavement.It can be seen that the OGFC pavement is superior to the other two types of pavements in terms of suppressing tire hydroplaning or reducing asphalt pavement water damage.In this paper,the hydrodynamic pressure distribution of tire and asphalt pavement under wheel load are studied,and the reference value of tire hydroplaning under different working conditions and water damage of asphalt pavement are provided. |
