Characterization of clastic rock using a biconcave bond model of DEM

Abstract

Summary This paper presents a biconcave bond model to investigate the effect of the cementation between grains on the mechanical behavior of rock. The proposed model considers the shape of the bonds among particles that have a biconcave cement form, based on observations of microscopic rock images. The general equations of the proposed model are based on Dvorkin theory. The accuracy and efficiency of the bond model is improved in three ways. After the biconcave bond model is implemented in the discrete element method software Particle Flow Code in 2 Dimensions, a series of numerical uniaxial compression tests were performed to investigate the relationships between the micro‐ to macro‐parameters. The simulations revealed that the biconcave bond model reflects the effect of micro‐parameters, such as the elastic modulus and Poisson's ratio of the cement, on the macroscopic deformation of cemented granular material. Variations in the bond geometry caused extremely diverse macro‐mechanical behaviors. Experimental results concerning rock demonstrate that the biconcave bond model accurately captures the mechanical behavior of intact rock and supports an innovative method for investigating the relationships between the micro‐ and macro‐parameters of cemented granular material. Copyright © 2016 John Wiley & Sons, Ltd.

Grain-Level Numerical Simulations for the Effective Elasticity of Weakly Cemented Sandstones

“…Grains in the CCT model are directly bonded together by a few intergranular cements near the contact area. It is worth noting that the small quantity of cementation by even very soft cements can significantly increase the stiffness of sands. , Chiu et al (2017) used the CCT model to develop a biconcave bond model to study the effect on the mechanical behavior of rocks. The CCT model usually holds for high porosity because of the minor amount of cement at grain contacts.…”