Effect of fast constant loading rates on the global behavior of sand in triaxial compression

Loading rate effects on the global stress-strain behavior of sand were investigated by performing triaxial compression tests on air-dried sand specimens. Siliceous and calcareous sands were subjected to triaxial compression at various constant strain rates to investigate the rate effects, initial density, confining pressure, shape and size of grains, as well as type of sand on the mechanical behavior of granular materials. The results indicate that silica sand and coral sand exhibit different rate dependency in terms of stiffness and peak normal stress. In general, strain rate effects are highly dependent on confining stress and relative density, with dense samples subjected to the highest employed confining stress exhibiting the most pronounced effects to variation in strain rates. Calcareous sand also exhibited a higher strain rate dependency than silica sand.