Issue 53

Y.D. Shou et alii, Frattura ed Integrità Strutturale, 53 (2020) 434-445; DOI: 10.3221/IGF-ESIS.53.34 434 Experimental and analytical investigation on the coupled elastoplastic damage model of coal-rock Yundong Shou* School of Civil Engineering, Wuhan University, China shouyundong@whu.edu.cn, https://orcid.org/0000-0001-7424-4006 Jianwei Zhang School of Civil Engineering, Chongqing University, China 20076188@cqu.edu.cn Filippo Berto Norwegian University of Science and Technology, Norway filippo.berto@ntnu.no A BSTRACT . In this paper, a novel coupled elastoplastic damage model for coal-rock is proposed to predict the deformation and potential disaster in coal mining. The conditions of small deformation and thermodynamic potential are considered, as well as the coupling of damage evolution process with the plastic deformation and the plastic hardening of coal-rock. Based on the theory of damage mechanics, the formulas of damage evolution, plastic yield and plastic potential of coal-rock are deduced theoretically. In addition, triaxial compression tests of coal-rock under the different confining stresses are conducted to reveal the law of deviatoric stress and strain. Based on the experimental data, the control parameters of the coupled elastoplastic damage model of coal-rock are determined. The theoretical results obtained from the coupled elastoplastic damage model for coal-rock agree well with those from the experiment. The proposed model is reasonable to predict the deformation of coal-rock. K EYWORDS . Coal-rock; Coupled elastoplastic damage model; Damage mechanics; Triaxial compression tests; The deformation prediction of coal- rock. Citation: Shou, Y.D., Zhang, J.W., Berto, F., Experimental and analytical investigation on the coupled elastoplastic damage model of coal-rock, Frattura ed Integrità Strutturale, 53 (2020) 434-445. Received: 23.04.2020 Accepted: 05.06.2020 Published: 01.07.2020 Copyright: © 2020 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION wo types of inelastic behaviors generally exist in most rock materials: plastic deformation, related to sliding mechanisms inside the microstructure of rock matrix; and damage to rock materials, induced by spreading microcracks[1-2]. In the case of semi-brittle rocks, for instance, limestone and porous sandstone, plastic deformation T