高应力作用下不同颗粒特征的钙质砂压缩破碎特性

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

摘要:

对南海不同岛礁处的钙质砂开展一系列终止压力为8 MPa的高压固结试验，研究不同颗粒形貌及不同粒组的钙质砂的颗粒破碎演化规律。试验结果表明，两种钙质砂试样S₁和S₂的矿物组分基本相同，但不同的沉积环境造成了颗粒形状具有显著差异；以片状颗粒为主的钙质砂试样S₂的压缩性和颗粒破碎程度会显著高于以块状颗粒为主的钙质砂试样S₁，且颗粒相对破碎率B_r均随着颗粒粒径的增大而增大；对两种不同的钙质砂而言，相对破碎率B_r与压缩变形量之间呈良好的幂函数递增关系，表明颗粒破碎大小与压缩变形量密切相关。

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.