Effect of the layer orientation on mechanics and energy evolution characteristics of shales under uniaxial loading

作     者：Hou Peng Gao Feng Yang Yugui Zhang Xiangxiang Zhang Zhizhen 

作者机构：State Key Laboratory for Geomechanics ＆ Deep Underground Engineering China University of Mining ＆ Technology Xuzhou 221116 China School of Mechanics ＆ Civil Engineering China University of Mining ＆ Technology Xuzhou 221116 China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2016年第26卷第5期

页      面：857-862页

核心收录：

学科分类：08[工学] 080104[工学-工程力学] 0815[工学-水利工程] 0801[工学-力学（可授工学、理学学位）] 

基　　金：supported by the National Key Basic Research Program of China (No. 2011CB201205) National Natural Science Foundation of China (No. 51204161) Innovation Project for Graduates in Jiangsu Province of China (No. KYLX15_1404) the Natural Science Foundation of Jiangsu Province of China (No. BK20140189) 

主　　题：Shale Layer orientation Energy evolutio Failure mechanism Uniaxial compression AE energy 

摘      要：The uniaxial compression tests were conducted on the cylindrical shale specimens with bedding plane inclined at 0° and 90° to the axial loading direction, respectively. Effect of the bedding orientation on the mechanical property and energy evolution characteristics of shales was revealed. The failure mechanisms of the specimens with layers in 0° orientation showed splitting failure along weak bedding, while the specimens with layers in 90° orientation were failed by shearing sliding. The values of compressive strength, elastic modulus and shear modulus of samples at 0° were higher than those of samples at 90°and there was little difference of Poisson s ratio between samples at 0° and 90°. The analysis of the stress–strain energy and acoustic emission(AE) energy indicated that the growth rate of absorbed energy density and elastic energy density at 0° was significantly faster than that at 90°, hence their final values at 0°were relatively larger than the latter. Moreover, higher energy release was observed for specimens at 0°.The energy release and rapid growth of energy dissipation also appeared more early at 0°. The stress ratio63% was a critical point of energy distribution at which differences started to arise between samples at 0°and 90°. These results indicated that the failure of shale at 0° was more violent and devastative than the failure of shale at 90°.