Study On Graded Granular-Flexible Base Of High-type Highway

Because of its superior bearing capacity, integral and durability, semi-rigid base has been the main pavement structure at home for many years. But, with the practical application and research on this kind of pavement structure used in high-type highway, many diseases including reflection cracks, one of the most important distresses occurred.In order to resolve these problems mentioned above, inverted pavement structure system has been put forward, in which flexible base is put on semi-rigid base. Based on the flexibility, reflection cracks can be eliminated effectively. Graded broken stone, which, as a kind of typical flexible base material, has excellent performance in flexibility, temperature-resistant and drainage.To learn more material and mechanic characteristics of graded granular, the dynamic tri-axial tests of this kind of graded aggregate in laboratory are conducted. And, comprehensive analyses on how to raise the bearing capacity have been done, for example, permanent deformation cannot be ignored and confining pressure is the key factor to add graded aggregate' s bearing capacity. According to the results, suggestions, which would contribute to the construction technology, are proposed. At the same time, considering the tendency of heavy load traffic and graded broken stone' s good property, the paper introduces the conception of theory of elasticity and plasticity, and focuses on discussing how to use the theory to analyze the flexible base of inverted pavement structural system.