부산대학교 도서관

The responses of three granular base materials were studied by stress path cyclic triaxial (SPCT) tests. These tests were cyclic triaxial tests along constant stress increment ratio paths where the radial stress was cycled simultaneously and in phase with the axial stress. SPCT tests can better simulate the stress changes experienced by typical elements of granular base materials in a pavement system during a wheel pass. The stress increment ratio (r), defined as the ratio of change in radial stress to change in axial stress, has a significant influence on the strain responses during cyclic loading. A parameter referred to as the proximity index was found to be most important in influencing the behavior pattern during cyclic loading. Provided the value of the proximity index is less than 0.7, the strain responses can be adequately modeled by a cross-anisotropic elastic model. However, the elastic stiffness parameters were correlated to both the number of loading cycles and the mean stress level and did not take a unique value.