Effect of particle shape on the liquefaction resistance of calcareous sands

摘要

The irregular particle shape is the significant feature of calcareous sands. It is known that calcareous sands generally show a higher liquefaction resistance than that of quartz sands, but the contribution of particle shape to the liquefaction resistance has not been well understood. In this paper, the particle shapes of calcareous sand, quartz sand and steel ball were quantitively assessed. Then, undrained monotonic and cyclic simple shear tests were conducted to investigate the influence of particle shape on the liquefaction resistance. The particle size and shape before and after simple shear were compared to assess the particle breakage. It is found that the degree of particle breakage is quite small, the surface grinding is the main mode, and the particle shape keeps almost unchanged during cyclic simple shear. Irregular sand particles show slow accumulation of excess pore pressure and need more cycles to trigger liquefaction in cyclic tests. It also shows the liquefaction resistance has a good linear correlation with the overall regularity of sand particles. Based on the fitting parameters, the liquefaction resistance of sand samples with different particle shapes can be directly obtained by the provided overall regularity of the sand particles.