Research On Analysis And Application Of Ultimate Bearing Capacity For Asphalt Pavements

Asphalt pavement is one of the main pavment structures in high-type highways at present. With the increase of over-load and heavy load vehicles in resent years, premature damage of asphalt pavements becomes a more popular phenomenon. Not all of the damages belong to the fatigue damage mode supposed by exist specifications. As the bearing capacity of a pavement structure is limited, excessive load may damage the pavement structure at one action. However, the definition of ultimate bearing capacity is still not introduced in the analysis and design of asphalt pavements around the world. As a result, it is an urgent engineering problem to determine load level on asphalt pavements scientificly and to research ultimate state design method of asphalt pavement structures.This thesis started with the analysis of traffic data collected on several typical roads in Hunan province. The axle load distribution and characteristics of heavy load asphalt pavements were studied. Based on axle load spectrum, a method to calculate the maximum design load of asphalt pavements was first studied according to reliability theory. Secondly, the mechanical respond of a typical asphalt pavement structure under heavy load was analyzed according to multilayer system elastic theory and characteristics of heavy loads, and analysis method of ultimate bearing capacity of asphalt pavements was advanced. Thirdly, ultimate bearing capacity theory was applied in the design of asphalt pavments. Ultimate state design method for asphalt pavment structures was put forward and illustrated by a specific example. Difference in design thickness by method of this paper and that of specifications was compared. Finally, theory analysis was conducted about the characteristics of three common construction loads, which are loads of self-dumping truck, tire roller and vibratory roller, and mechanical calculation models were established for three loads. For the mechanical analysis of pavements under vibratory roller, it was considered as a problem of plane strain, and then analysis result of stress and displacement of pavement structures was obtained. For convenience of calculation, the corresponding computer program was compiled with language of VC++. On basis of this, mechanical responses of pavement structures under construction loads were analyzed, taking different construction phases of an asphalt pavement and different ages of pavment material into account. The ultimate bearing capacity was analyzed according to...