Numerical Analysis Of Asphalt Pavements Under Coupled Vehicle Load And Water

According to the existing research results,the pore hydrodynamic pressure caused by vehicle load in asphalt pavement is an important inducement for moisture damage of asphalt pavement structure.As things stand,mechani cs research of asphalt pavement is not comprehensive enough in domestic and abroad,and the content of the study is less,especially for mechanics computing research of permeable asphalt pavement which is more and more widely used and discussed in recent years.In addition,the influence of water for the mechanical properties of asphalt pavement is also lack of profound study,and the splitting effect of pore hydrodynamic pressure produced under the action of vehicle loads is often neglected in the cracks a nalysis.Asphalt pavement material is equivalent to three-phase system based on principle of porous media and introduction of biot consolidation theory.This paper establishes finite element analysis model under coupled water and vehicle load by using the software ABAQUS.Also,this paper analyzes the law of hydrodynamic pressure inside the various kinds of asphalt surface material,the influence of the surface drainage conditions and permeable asphalt pavement form on the pore hydrodynamic pressure.This paper analyzes the variation of pore hydrodynamic pressure in asphalt surface layer under different vehicle speed.This paper analyzes the influence of water on the mechanical properties of asphalt pavement.On the basis of hydraulic coupling calculation of asphalt pavement structure and with the consideration of the symmetrical load and the offset load relative to the crack position,and different lengths of asphalt surface cracks,this paper analyzes the stress field and displacement field of permeable asphalt pavement structure near the crack tip under the condition of vehicle load and hydraulic coupling.This paper calculates the corresponding tensile and shear stress intensity factors,and does the comparison of the result with ordinary asphalt pavement structure.Finally,the influence of the pore hydrodynamic pressure generated by the vehicle load has on the existing crack of asphalt pavement structure is determined.The results showed that the stress field and displacement field of asphalt pavement structure have changed greatly compared with the water free state because of the hydrodynamic pressure.Water has an adverse effect on the stress state of asphalt pavement structure.In both base course and bottom layers of asphalt pavement structure under water-saturated condition,horizontal tensile stress and compressive stress alternating phenomenon were produced,which will lead to fatigue damage in pavement structure materials.In addition,the hydrodynamic pressure also has the splitting effect on the crack in the asphalt surface layer,and the tensile cracking of the crack will be promoted,and the more hydrodynamic pressure is,the more obvious the effect is.No obvious effect on shear cracking is found.The permeable asphalt pavement structure has better drainage performance,which can effectively relieves the splitting effect of hydrodynamic pressure on the existing crack in asphalt surface.