Particle Breakage and the Drained Shear Behavior of Sands

This paper presents particle breakage and the drained shear behavior of sands. A series of drained shear tests were conducted on Silica Sand No. 5 and Coral Sand No. 3 under a 3-MPa confining pressure to produce the precrushed sands that were reused in triaxial tests to detect the influence of particle breakage. It was revealed that, for a given initial void ratio, particle breakage resulted in the impairment of the dilatancy of sands to become more contractive in influencing the shear behavior of the precrushed sands. Particle breakage resulted in the reduction of the peak-state friction angle and dilatancy angle, but the peak-state basic friction angle (the difference between peak-state friction angle and peak-state dilatancy angle) experienced first an increase and then a decrease with increasing particle breakage. For estimating the dilatancy angle by the excess friction angle (the difference between the peak-state friction angle and the critical-state friction angle), particle breakage was shown to have a significant influence on the friction-dilatancy behavior, including the accuracy of the excess friction angle to assess the peak-state dilatancy angle. The relations of the strengths and the void ratios of the precrushed sands were discussed as well. In addition, particle breakage resulted in a decrease of the critical-state void ratio but had a complex influence on the critical-state friction angle.