CHARACTERIZATION OF SATURATED GRANULAR BASES UNDER REPEATED LOADS

Abstract

The behavior of typical granular materials with different gradation was investigated under saturated, undrained, repeated triaxial loading conditions. Of particular interest is the comparative behavior of open-graded and dense-graded base courses and the influence of fines content on the dynamic response. The effect of aggregate gradation on the cyclic stress-strain behavior, pore pressure, damping, resilient modulus, compressibility, and permeability is investigated. Results indicate that saturated granular materials will develop excess pore water pressure under undrained repeated triaxial loading. This could lead to a decrease in resilient modulus and a potential increase in volume compressibility. Open-graded aggregates are more resistant to pore pressure buildup than dense-graded aggregates and are therefore less likely to induce damage in pavements under saturated conditions. In this respect, the estimated damage per repetition could be as much as 70 to 100 times more for pavements with dense-graded bases.