Orthogonal Analysis on Structure Design Parameters of Flexible Base Asphalt Pavement

The typical structures of flexible base asphalt pavement at home and abroad are comprehensively analyzed.The effect of key structure parameters on two performance indicators of flexible base asphalt pavement,that is the rebound deflection of pavement surface and the pitch stress at the bottom of asphalt layer,is studied by the orthogonal method.These key structure parameters includes the depth of asphalt treated base and unbound graded aggregate base,the module of sub-grade and so on.The results show that:the module of sub-grade has important influence on rebound deflection of pavement surface;increasing the thickness of asphalt layer can reduce the tensile stress at the bottom of asphalt layer and prolong the fatigue life of asphalt pavement;however,the thickness of asphalt layer has little effect on prolonging the fatigue life of asphalt pavement when the total thickness of asphalt layer exceeds 25cm.