Experimental and numerical study of the failure process and energy mechanisms of rock-like materials containing cross un-persistent joints under uniaxial compression

PLoS One. 2017 Dec 12;12(12):e0188646. doi: 10.1371/journal.pone.0188646. eCollection 2017.

Abstract

Joints and fissures in natural rocks have a significant influence on the stability of the rock mass, and it is often necessary to evaluate strength failure and crack evolution behavior. In this paper, based on experimental tests and numerical simulation (PFC2D), the macro-mechanical behavior and energy mechanism of jointed rock-like specimens with cross non-persistent joints under uniaxial loading were investigated. The focus was to study the effect of joint dip angle α and intersection angle γ on the characteristic stress, the coalescence modes and the energy release of jointed rock-like specimens. For specimens with γ = 30° and 45°, the UCS (uniaxial compression strength), CIS (crack initiation stress) and CDiS (critical dilatancy stress) increase as α increases from 0° to 75°. When γ = 60° and 75°, the UCS, CIS and CDiS increase as α increases from 0° to 60° and decrease when α is over 60°. Both the inclination angle α and intersection angle γ have great influence on the failure pattern of pre-cracked specimens. With different α and γ, specimens exhibit 4 kinds of failure patterns. Both the experimental and numerical results show that the energy of a specimen has similar trends with characteristic stress as α increases.

MeSH terms

  • Compressive Strength*
  • Data Compression*
  • Stress, Mechanical*

Grants and funding

This study was funded by National Natural Science Foundation of China, grant numbers 11772358, 51404179, to Ping Cao (http://faculty.csu.edu.cn/caoping/zh_CN/yjgk/27500/list/index.htm); National Natural Science Foundation of China, grant numbers 51774322, 51474249, to Hang Lin (http://srse.csu.edu.cn/channels/1058.html); Innovation Driven Plan of Central South University, grant numbers 2016CX019, to Hang Lin (http://srse.csu.edu.cn/channels/1058.html); Graduate Student Innovation Project of Central South University, grant numbers 2015zzts074, to Dr Ri-hong Cao; Fundamental Research Funds for the Central Universities, grant numbers 310821161008, to Hang Lin (http://srse.csu.edu.cn/channels/1058.html); Opening Fund of the State Key Laboratory of Geo-hazard Prevention and Geo-environment Protection, grant numbers SKLGP2016K009, to Hang Lin (http://srse.csu.edu.cn/channels/1058.html).