BEARING CAPACITY OF UNPAVED ROADS

Elastic layer theories may be valid for relatively stiff pavement mate rials and pavements subjected to low traffic stresses; however, the as sumption of linear elastic behavior is not suitable for thin pavements and unpaved roads consisting of untreated granular bases over cohesiv e subgrades. The behavior of such pavements, even al low traffic stres ses, is markedly nonlinear. Pavement design methods based on a bearing capacity theory are more applicable to roads with thin pavements, Thi s paper outlines an ultimate strength method of designing low-volume r oads. A procedure for determining the ultimate loads in layered system s, incorporating the effect of matric suction, is also presented. Exis ting empirical relationships that account for traffic loading are util ized in the proposed design procedure.