Macro and meso analysis of jointed rock mass triaxial compression test by using equivalent rock mass (ERM) technique

ZHOU Yu(周喻)^{1, 2}, WU Shun-chuan(吴顺川)¹, GAO Yong-tao(高永涛)¹, A. Misra²

(1. Key Laboratory for Efficient Mining and Safety of Metal Mine of Ministry of Education of China
(University of Science and Technology Beijing), Beijing 100083, China;
2. School of Engineering, University of Kansas, KS 66045-7609, USA)

Abstract:Methods that can efficiently model the effects of rock joints on rock mass behavior can be beneficial in rock engineering. The suitability of equivalent rock mass (ERM) technique based upon particle methods is investigated. The ERM methodology is first validated by comparing calculated and experimental data of lab triaxial compression test on a set of cylindrical rock mass samples, each containing a single joint oriented in various dip angles. The simulated results are then used to study the stress-strain nonlinearity and failure mechanism as a function of the joint dip angle and confining stress. The anisotropy and size effects are also investigated by using multi-scale cubic ERM models subjected to triaxial compression test. The deformation and failure behavior are found to be influenced by joint degradation, the micro-crack formation in the intact rock, the interaction between two joints, and the interactions of micro-cracks and joints.

Key words:jointed rock mass; discrete element method; equivalent rock mass technique; macro; meso