Effects of Load Duration and Stress Level on Deformation and Particle Breakage of Carbonate Sands

Abstract

Time-dependent deformation of crushable soils attributable to particle breakage could dominate the postconstruction stability of high rockfill dams and pile foundations. The evolutionary trends of the volumetric strain, particle-size distribution (PSD), and particle breakage of carbonate sands with 10% fines content for various loading durations and vertical stress levels are investigated by performing a series of one-dimensional compression tests. Loading durations ranging from 1 to 10,000 min, vertical stress levels ranging from 200 to 3,200 kPa, and fines content percentages ranging from 0 to 20 are considered. The results indicate that the increased loading duration in the initial stage has a significant effect on the volumetric strain; however, as the loading duration increases, this effect gradually decreases. In addition, the PSD curve shifts upward as the loading duration increases, indicating that the amount of particle breakage increases accordingly. Both the loading duration and the vertical stress can induce PSD changes in carbonate sands. Empirical equations are proposed to describe the relationship between the relative particle breakage index and the loading duration as well as the relationship between the relative particle breakage index and the vertical stress.