Impact Factor Analysis Of Reflective Cracking In Semi-Rigid Base Asphalt Pavement Under Dynamic Triffic Loading

Based on the design principle of"intense base,thin surface-layer,steady foundation", semi-rigid base asphalt pavement structure was widely used in the high-way construction in China. But this kind of asphalt pavement structure shall bring diversified problems especially reflective cracking. So, it's a dominating matter that reflective crack in semi-rigid base asphalt pavement to be figured out urgently.Firstly, a planar finite element model which is based on the study both domestic and overseas and on the request of"Specifications for Design of Highway Asphalt Pavement", also on the samdwich-system theory is established in ANSYS according to the traditional design method. In this part, the author mainly analyzes the influence between the stress intensity factor (SIF) and parameter such as materials'modulus,thickness, the crack length and the load magnitude under static load, then gives out the rational range of each parameter.Secondly, according to the established FEA model, in order to study the impact between SIF and parameter like materials'characteristics and the crack length, a syntonic dynamic analysis is carried on both symmetrical and deflective dynamic traffic loads which was simplified to a foursquare distributed half-sine dynamic loading. From the calculation, it points out that the crack-length as well as the modulus and the thickness of the surface-layer are the most influencing factor to the SIF.Finally, grounded on the existing researchful results, a rough analysis is carried out to investigate the diversification after setting several different stress-absorptive layers in the asphalt pavement structures. Correspondingly, from the point of the structure-assemble it proposes a few crack-proof measures to prevent or decrease the enlarging of the crack.