Effect of particle morphology on stress and strain characteristics of granular materials during triaxial compression

Soil particles possess highly complex particle morphology, including particle shape and surface roughness, which have a significant impact on mechanical responses of granular materials, such as packing characteristics, small-strain stiffness and stress–strain responses. However, there has been little or no quantitative investigation on the combined effect of particle shape and surface roughness. This contribution carries out triaxial compression tests using six differently shaped granular materials under dry and drained conditions. Meanwhile, the surface texture is carefully treated to vary the degree of surface roughness for each material. Samples are prepared under a similar initial void ratio ( e 0 ) or relative density ( D r0 ) to eliminate the density-dependency. Samples prepared under the same sample preparation method with a given tapping number ( N t ) during the sample preparation process are also considered. The experimental results show that more irregular materials tend to show greater values of deviator stresses at the peak state ( q peak ) and an axial strain of 15