Experimental and numerical study on mechanical and fracture behavior of rock-like specimens containing pre-existing holes flaws

作     者：Zhao, Zhenlong Jing, Hongwen Shi, Xinshuai Han, Guansheng 

作者机构：China Univ Min & Technol State Key Lab Geomech & Deep Underground Engn Xuzhou 221116 Jiangsu Peoples R China Nagasaki Univ Grad Sch Engn Nagasaki Japan 

出 版 物：《EUROPEAN JOURNAL OF ENVIRONMENTAL AND CIVIL ENGINEERING》 (欧洲环境与土木工程学杂志)

年 卷 期：2022年第26卷第1期

页      面：299-319页

核心收录：

学科分类：08[工学] 0818[工学-地质资源与地质工程] 0813[工学-建筑学] 0814[工学-土木工程] 

基　　金：National Natural Science Foundation of China [51734009  51704279  51709260] 

主　　题：Pre-existing holes fracture mode acoustic emission progressive failure process particle flow code 

摘      要：Laboratory tests and numerical simulation are conducted to study mechanical behavior of rock containing two pre-existing holes in this paper. First of all, rock-like specimens containing two pre-existing holes were prepared to investigate mechanical and acoustic emission characteristics in the uniaxial compression. Different geometries were obtained by changing the angle of the center line of holes with respect to the direction of axial loading. Experimental results show that the stress-strain curves present obvious fluctuation, and evolution process of acoustic emission signal can be divided into four stages. There are three kinds of failure modes: only shear failure, mainly shear and auxiliary tensile failure, mainly tensile and auxiliary shear failure. Then, parallel bonded mode (PBM) based on the particle flow code in two dimensions (PFC2D) were established to study strength and failure modes in the biaxial compression. Finally, process of cracks initiation, propagation and coalescence, and fracture mechanism were further discussed. The most important conclusion reached is that the deformation and failure process of rock mass containing holes defects can be divided into two stages: rock bridge penetration and overall instability, which are sequential.