Control of designing indices for asphalt pavement with different types of base

Based on the reconstruction and extension project of Xitong expressway,the fatigue and breakage forms of semi-rigid asphalt pavement,compound base asphalt pavement and flexible base asphalt pavement were analyzed and the corresponding design parameter system was established separately.The sensibility of the materials parameter as the mechanical responses was analyzed using Shell designing software Bisar3.0,which verified the rationality of pavement de-signing indices from the point of stress balance.The results show that taking flexible strain and surface shear stress as designing indices for flexible pavement could keep the modulus value of semi-rigid base in proper range.Taking flexible stress of base and shear stress of base as designing indices for semi-rigid pavement and compound pavement could constraint the modulus value of semi-rigid base.The introduction of shearing stress is particularly necessary for asphalt pavement design because it can seriously affect material parameters and help optimize both the structure and material design.