Analysis And Research On The Behavior Of Asphalt Pavement And Roadbed Under Heavy Load

With the rapid growth of economy,the transportation industry is also showing a sign of vigorous development,the largest,most overloading in road transportation vehicles and overload vehicles than column increasing increasingly,and has gradually become a common phenomenon.It makes the road of cumulative equivalent shaft time increased significantly,the original road design specification has to meet the increasing brought by the service requirements of heavy load,make the highway asphalt pavement and roadbed in heavy load under the action of repeated appear prematurely rut,crack and other early damage,make its service life of road.In this paper,based on PuXuan expressway in yunnan xuanwei,which depends on the project area as the important coal-producing area of yunnan,due to its economic development factors,the service area PuXuan expressway has the characteristics of uniaxial heavier,traffic is bigger,years of service in heavy load traffic conditions,the roadbed and road surface appear prematurely damage.In addition,due to the geographical location of the highway,the climate of the region is humid,the rainfall season is much higher,the average annual temperature is low,the annual temperature difference is small,and the daily temperature difference is large.In view of the above situation,this article on the basis of the status quo at home and abroad for reference,the first use of equivalent standard axle load coefficient and conversion way from axle load under the condition of heavy load traffic asphalt pavement damage value is far beyond the actual design allowable values.Followed by using numerical simulation and laboratory test,in view of the highway asphalt pavement typical structure analysis of pavement structure,semi-rigid pavement structure base material,using the finite element software to calculate the axial load in the standard,the pavement structure without affected by water and water is the most serious in both cases,the stress and strain distribution of parts within the pavement structure,on the basis of further research through indoor fatigue cracking test to determine the fatigue life of asphalt road surface.Finally concluded that the maximum tensile stress in surface layer below will be decreased with the increase of road surface temperature,and the change trend of maximum tension should be changed,on the other hand,under the condition of serious water damage state compared with anhydrous conditions makes the pavement layer below the maximum tensile strain and tensile stress are increased.Next the fatigue life of asphalt surface and water damage and has close relation with the load,when the water damage and load effect on the road at the same time,the fatigue life only two-thirds of the anhydrous state conditions.Temperature is also the main factor affecting the life of asphalt mixture.With the increase of temperature,the fatigue life of asphalt mixture will decrease significantly.The related characteristics of roadbed play a decisive role in the overall stiffness,strength and overall service level of the road structure,especially the stress-strain characteristics.This article by ANSYS finite element calculation software of subgrade soil under the condition of different wheel pressure,its,subgrade soil internal stress analysis,and to determine the workspace of subgrade soil under heavy load,using the empirical formula presented by Li and Selig method on the accumulation of soil deformation forecast estimates.The conclusion can provide reference for the design and construction of asphalt pavement and roadbed in this area.