Research on influences of particle breakage and dilatancy on shear strength of calcareous sands

Calcareous sediments generally consist of the remains of marine organism, which tend to crush relatively easily under load, compared to terrigenous materials. Based on the data of triaxial shear tests carried out on calcareous sand taken from the South China Sea, the influences of the particle breakage and dilatancy on shear strength of calcareous sands are discussed and analyzed. The results indicate that the particle breakage and dilantacy have significant effect on the shear strength of calcareous sands. The effect of the dilatancy on the shear strength is more serious than that of the particle breakage under low confining pressure, while with the confining pressure increasing, the effect of the particle breakage increase and that of dilatancy decrease. When the confining pressure attained to some extent, the particle breakage and its effect on shear strength will diminish.