Theoretical and experimental analysis on the mechanism of the Kaiser effect of acoustic emission in brittle rocks  

作　　者：Ruifu Yuan Yuanhui Li 

机构地区：[1]School of Energy Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China [2]College of Resource and Civil Engineering, Northeastern University, Shenyang 110004, China

出　　处：《Journal of University of Science and Technology Beijing》2008年第1期1-4,共4页北京科技大学学报（英文版）

基　　金：the National Natural Science Foundation of China(No.50474017).

摘　　要：The Kaiser effect is formally described as the absence of detectable acoustic emission （AE） events until the load imposed on the material exceeds the previous applied level and is usually used to estimate geostress. By focusing on the heterogeneity of rock material, the mechanism of the Kaiser effect under cyclic loading is analyzed based on statistic damage mechanics. Two groups of granite specimens have been cyclically loaded with two different loading paths to verify the theoretical results. The heterogeneity of rock is the real reason that causes irrecoverable damage on the Kaiser effect of acoustic emission in cyclic loading. The Kaiser effect reflects the damaged state in rocks rather than the previous stress imposed on it. Applications for using the Kaiser effect to estimate geostress were discussed here. It is shown that the commonly used uniaxial loading method for estimating geostress is not in accor- dance with the theoretical and experimental results. The analysis is of importance to use the Kaiser effect correctly for estimating geostress or in other fields. 2008 University of Science and Technology Beijing. All rights reserved.The Kaiser effect is formally described as the absence of detectable acoustic emission （AE） events until the load imposed on the material exceeds the previous applied level and is usually used to estimate geostress. By focusing on the heterogeneity of rock material, the mechanism of the Kaiser effect under cyclic loading is analyzed based on statistic damage mechanics. Two groups of granite specimens have been cyclically loaded with two different loading paths to verify the theoretical results. The heterogeneity of rock is the real reason that causes irrecoverable damage on the Kaiser effect of acoustic emission in cyclic loading. The Kaiser effect reflects the damaged state in rocks rather than the previous stress imposed on it. Applications for using the Kaiser effect to estimate geostress were discussed here. It is shown that the commonly used uniaxial loading method for estimating geostress is not in accor- dance with the theoretical and experimental results. The analysis is of importance to use the Kaiser effect correctly for estimating geostress or in other fields. 2008 University of Science and Technology Beijing. All rights reserved.

关 键 词：brittle rocks cyclic loading Kaiser effect acoustic emission loading path DAMAGE 

分 类 号：TF041[冶金工程—冶金物理化学]