The results from a series of large-scale triaxial tests on dense gravel, prismatic specimens with dimensions of 50 cm in height and 23 cm times 23 cm in cross-section, are described. Specimens were prepared at density equal to approximately 95% of the maximum density at optimum moisture content. Deformations were measured locally using vertical and horizontal local deformation transducers. Stress conditions with very low confining pressure were used to simulate specific conditions at road and railway embankments. Particular attention was paid on bedding error at the top and bottom ends of specimen and on fixing the transducers on membrane to be used under low confining pressure. The confining pressure has been applied by vacuum and varied from 10 kPa to 75 kPa. Unsaturated specimens were tested in drained triaxial compression, using monotonic and cyclic loading with a frequency of 0.5 Hz to 5 Hz.
The effects of large number of preloading cycles and specimen overloading were investigated.