Influence of Mineral Composition on the Simple Shear Response of Sands: Experimental Study

Abstract

Experiments were conducted to evaluate the role of mineral composition on the direct simple shear response (i.e., volume change during shear) of uniform sands composed of “strong” quartz grains and “weak” calcareous grains. The dry specimens were loaded in a custom-made direct simple shear apparatus and separated after testing with respect to grain size by sieving and with respect to mineral composition by dissolving the calcareous grains retained on each sieve. The results indicate that the presence of weak grains affects the direct simple shear response of predominately strong-grained sands: at low stresses, the response is controlled by particle shape; at high stresses, the response is controlled by weak particle breakage.