Effect of Micro-Structure on the Macroscopic Behavior of Cemented Granular Material

摘要

In order to improve the physical understanding of the phenomenology associated with the deformation of highly porous geologic materials such as alluvium, the details of inter-granular rolling, shearing and extension have been studied for cemented particles. Two-dimensional analytic expressions are derived that relate the response of two bonded particles to deformations of an elastic adhesive material. A two-dimensional version of the distinct element code, TRUBAL, was modified by incorporating these analytic relations into the calculational sequence. A modified Griffith criterion isused to trigger inter-particle fracture in quasi-static and dynamic regimes. The details of the implementation of these features into TRUBAl are decribed and the necessary modifiations to the stress tensor calculation are developed. The evolution of multiple particle clusters is investigated in several quasi-static and dynamic numerical experiments. The calculational results are compared to laboratory data and macroscopic constitutive laws. Scanning electron micrographs and thin section photomicrographs are provided, illustrating some strengths and limitations of the model. 50 refs., 153 figs., 8 tabs. (ERA citation 13:031373)