Compression and Fragmentation Characteristics of Calcareous Sand with Different Grain Characteristics at High Stress

Abstract:

A series of high-pressure consolidation tests on two kinds of calcareous sand were conducted at a termination pressure of 8 MPa to study the particle breaking evolution of the calcareous sand with different particle morphologies and different particle groups. The test results show that the mineral components of the two calcareous sand samples （S₁ and S₂） are basically the same， but the different depositional environments have caused significant differences in particle shape. The compressibility and the breakage rate of the calcareous sand （sample S₂，） which is dominated by flaky particles are both significantly higher than that of the calcareous sand （sample S₁）， which is dominated by massive particles， and for these two samples， the relative particle breakage rate Br increases with the increase of particle size. For the two different calcareous sand， there is a good power function increasing relationship between the relative rate of crushing B_r and the amount of compression deformation， indicating that the degree of particle breakage is closely related to the amount of compression deformation.

Key words:high-pressure consolidation;calcareous sand;particle shape;particle breakage;compression deformation