Micro-mechanical Experimental Investigation of Grain-to-Grain Sliding Stiffness of Quartz Minerals

Abstract

The study presents micro-mechanical tests at the contacts of quartz soil grains exploring the inter-particle sliding (tangential) stiffness through tests of a force-controlled type. The experiments are conducted in a custom-built micromechanical apparatus which is capable to study the particle contact response at relatively low confining forces. This makes its configuration more appropriate for soil mechanics purposes. The experimental data indicated a dependency of particle-contact sliding stiffness (KT0) on the level of normal force (FN) with almost a linear increase of KT0 with FN for the range of normal forces of the study. The results of the research work could be incorporated directly as input in numerical simulations that use the discrete element method for a more realistic representation of the behavior at soil grain contacts.