Effect of heterogeneity on mechanical and micro-seismic behaviors of sandstone subjected to multi-level cyclic loading: A discrete element method investigation

In numerical simulation of the mechanical responses and acoustic emission (AE) characteristics of rocks under cyclic loading, the impacts of compositional heterogeneities of mineral grains have barely been considered. This will lead to a poor reproduction of rock's behaviors in terms of stress-...

Full description

Bibliographic Details
Main Authors: Zhengyang Song, Zhen Yang, Min Zhang, Fei Wang, Martin Herbst, Heinz Konietzky
Format: Article
Language:English
Published: Elsevier 2023-10-01
Series:Journal of Rock Mechanics and Geotechnical Engineering
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1674775523000495
Description
Summary:In numerical simulation of the mechanical responses and acoustic emission (AE) characteristics of rocks under cyclic loading, the impacts of compositional heterogeneities of mineral grains have barely been considered. This will lead to a poor reproduction of rock's behaviors in terms of stress-strain relationship and micro-seismic characteristics in numerical simulation. This work aims to analyze and reveal the impact of parameter heterogeneity on the rock's fatigue and micro-seismic properties based on PFC3D. Two distribution patterns (uniform and Weibull distributions), are implemented to assign four critical parameters (i.e. tensile strength, cohesion, parallel bond stiffness and linear stiffness) for 32 sets of numerical schemes. The results show that the models with high heterogeneity of tensile strength and cohesion can better reproduce the stress-strain relationship as well as the patterns of cumulative AE counts and energy magnitude. The evolution of the proportion of three-level AE events in the laboratory test is consistent with the numerical results when the highly heterogeneous tensile strength and cohesion are distributed. The numerical results can provide practical guidance to the PFC-based modeling of rock heterogeneity when exposed to multi-level cyclic loading and AE monitoring.
ISSN:1674-7755