The Study Status Of The Impact Of Heavy Axle Load To Shakedown Theory For Road Pavements

Since twenty-first Century,China's national life level increases rapidly,and at the same time,the national demand for transport capacity is increasing.In order to satisfy the people to transport fast,large amount of demand,heavy axle load vehicles emerged.In recent years,the number of heavy vehicles,the rapid growth in the transport of goods accounted for the total transportation volume ratio heavy vehicles,is rising.However the heavy axle heavy vehicle load to bring road has brought great harm,on the road in the early in the ruts,pits,cracks,subsidence and breakage,thus greatly shorten the service life of the pavement,causing huge economic losses in the transport sector.This paper research The heavy axle load of subgrade deformation characteristics,introduces the concept of stability,put forward the analysis method for stability of subgrade soil,discusses the heavy axle load on the subgrade stability influence,main work and achievements are as follows:(1)Study of heavy traffic load.The schema axle load survey and test of typical heavy load,load spectrum draw axis.Researchers in China for heavy haul by increasing the tire contact area and to carry out the analysis of pavement structure analysis method of constant pressure assumed round,but the actual situation is heavy on the road through the use of high-strength overweight vehicles tires and tire increase the pressure to ensure the increase of axle load does not affect the normal running of the vehicle,so the existing standard schema calculation errors of the results and the actual situation.According to the characteristics of the heavy vehicle and pavement,recommended the use of the Belgian style schema as mechanical schema,tire contact area by A=0.008P+152 Calculation.(2)Study on characteristics of stress and deformation in the heavy axle load under the subgrade soil.In 2 under the vehicle load,road self gravity,in a certain range of depth,subgrade and foundation soil in the bearing state.Vehicle load have a greater stress in this depth range is called the subgrade work area in Subgrade with.The increase of axle load,subgrade work area was deepened,in order to ensure the subgrade work area of embankment in the range necessary for increasing the height of the embankment,and in order to guarantee the stability of embankment with high embankment and embankment widening width,which will increase the economic cost of road and occupy more land resources.(3)Use BISAR program to calculate the different pavement structure under different axial load and different tire pressure under subgrade compressive strain,the results show that when the tire pressure is the same,with the increase of axial load compression strain on top of subgrade increased obviously.So the axial load increases affect the strength of the subgrade is huge,there is a greater destructive effect on the subgrade.(4)Introduce the stability theory,to investigate the heavy axle load effect on the stability of the road.Through the cyclic uniaxial test and simulation test of subgrade soil,critical plastic stress and failure stress level of subgrade soil plastic deformation characteristics and determine the highway subgrade soil should be added in three kinds of stress strain behavior under the level of different animals.