3-DIMENSIONAL ANISOTROPIC SWELLING MODEL FOR CLAY SHALE - A FABRIC APPROACH

A three-dimensional model is developed to quantify the anisotropic swe lling behaviour of geological materials. The model considers clay mine ral particle swelling, fabric anisotropy and induced stress anisotropy as important fundamentals. The double layer theory is used to describ e the relationship between the interactive particle stress and the swe lling strain. Continuous functions are introduced to represent the fab ric density and the particle stress distributions and to permit contin uum analyses of three-dimensional swelling problems. The performance o f the model has been evaluated against the experimental data obtained from swell tests on a clay soil and two clay shales. It is found that the model provides reasonable predictions on the swelling behaviour of high-density clay shale in which the swelling is dominated by the mic rostructural particle swelling rather than the macrostructural matrix deformation. (C) 1997 Elsevier Science Ltd.