关键词: 颗粒形状, 颗粒破碎, 临界状态, 二元介质模型, 强度准则

Abstract: In order to explore the influence of particle shape on the particle fragmentation and strength characteristics of granular materials, this paper proposes a new parameter to quantify the particle shape of granular materials, designs an artificial sample preparation method considering the three-dimensional particle shape feature information, then conducts a conventional triaxial compression test for these prepared samples, and analyzes the particle local breakage law and strength characteristics, finally derives a binary medium strength criterion. Some research results are drawn as follow. Quantitative parameter of particle shape—spherical modulus G_M is proposed. On this basis, five different shapes of triaxial specimens of crushable granular materials were prepared, and it is found that the spherical modulus affects the triaxial compressive strength characteristics of granular materials. The particle breakage of the sample is determined by sieving method, and the evolution law and critical state of the sample particle breakage is discussed, and particle shape is found to control the nonlinear evolutionary characteristics of macroscopic strength by influencing the particle fragmentation pattern. Based on the binary medium theory, the strength criterion of crushable granular materials considering the particle shape is established, and its applicability is verified by experiments results from conventional triaxial condition.

Key words: particle shape, particles crushing, critical states, binary medium model, strength criterion