单轴多级加载岩石破坏声发射特性试验研究.pdf

25 12 Vol.25 No.12 2006 12 Chinese Journal of Rock Mechanics and Engineering Dec .2006 1 12 1 1 1 (1. 610065 2. 100083) AE AE AE AE AE TU 452 A 1000 6915(2006)12 2584 05 EXPERIMENTAL STUDY ON ACOUSTIC EMISSION CHARACTERISTICS OF ROCK FAILURE UNDER UNIAXIAL MULTILEVEL LOADINGS 1 12 1 1 1 ZHANG Ru XIE Heping LIU Jianfeng DENG Jianhui PENG Qi (1. College of Water Resources and Hydropower Sichuan University ChengduSichuan610065China 2. Institute of Rock Mechanics and Fractals China University of Mining and TechnologyBeijing100083China) Abstract Experiments on acoustic emission(AE) characteristics of complete granite failure process are carried out under uniaxial multilevel loadings. Relations between stress and strain and relations of time with AE characteristics and stresses are obtained. The results show that during load stability periodAE rate and AE energy decrease but AE events remain constant approximately which show that cracks are not developed and AE level is low. During load increase periodAE rate raises indicating that cracks are developed. The uniaxial multilevel loading experiments reflect AE trend during stress regulation to certain degree when underground powerhouse is excavated step by step. It is suggested thatfor rockburst geologic hazardsappropriate monitoring opportunity should be adopted during AE monitoringespecially AE monitoring should be strengthened when the upper and nether steps are joined. AE progress of rock failure includes initial phase tempestuous phase and drop phase. When the curve reaches to its peak phase major AE of events rock sa