抄録
The mechanical properties of sands change notably with a variation of confining stress. In some geotechnical problems, such as the bearing capacity problem of shallow foundations on sand ground, the confining stress dependency of sand mechanical behavior plays an important role as a stress level effect. In this study deformation-failure behaviors of some 80 granular materials with various primary properties were observed in a series of triaxial compression tests covering a range from low to medium high confining stresses. From experimental results, the dependency of the deformation-failure behaviors of sands on confining stress was comparatively examined, and the degree of confining stress dependency was evaluated by the indices introduced in this study. The influence of primary properties, such as density, hardness, shape and size of grains, on the degree of confining stress dependency is the main subject of this study. From test results, it was found that the mechanical properties of sands vary markedly with a change in confining stress, and the degree of confining stress dependency varies with the primary properties. The degree of confining stress dependency can be estimated from some index properties ; void ratio extent (emax-emin) was selected as a promising parameter for evaluating the confining stress dependency of the deformation-failure behaviors of sands.
