(1. College of Environment and Civil Engineering，Chengdu University of Technology，Chengdu，Sichuan 610059，China； 2. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection，Chengdu University of Technology，Chengdu，Sichuan 610059，China)
Abstract：Accurate identifying each stage characteristic stresses of rock has significant importance on determining rock deformation and failure stage，mechanics，design parameters. In view of this，the “testing data+ strain stiffness” combing method has been proposed to identify those stresses. According to the trixial compression testing data of sandstone(30 MPa)，the operation process has been detailed，and the method has been verified. Then the following conclusions can be drawn：(1) The linear elastic feature is obvious in stress-strain curve，but the demarcation point of the linear elastic stage and the stable crack growth stage is not easy to be detected；(2) The tiny changes in stress-strain curve can be amplified by strain stiffness，which is better used to identify the rock deformation stages，and the strain stiffness curve can be divided into five stages：irregular fluctuation，regular fluctuation and nearly horizontal，irregular fluctuation and gradually decreasing to zero，extremely fluctuation，nearly zero.(3) The serious irregular fluctuations in strain stiffness are related to the events of the crack closure，initiation，expansion，coalescence，rock failure and block sliding；(4) The ratio of crack closure stress，crack initiation stress and damage stress to peak stress are 0.10，0.56 and 0.68 respectively. (5) Based on first derivative，objective and reasonable operation process，the method is an accurate in theory and semi-accurate in operation method. Finally，with the modern computer and data processing technology，the processing can be easily operated；providing a new approach to identify rock characteristic stress.
高美奔1，2，李天斌1，2，孟陆波1，2，陈国庆1，2，陈 超1，2，廖安杰1，2，罗 凯1，2. 岩石变形破坏各阶段强度特征值确定方法[J]. 岩石力学与工程学报, 2016, 35(S2): 3577-3588.
GAO Meiben1，2，LI Tianbin1，2，MENG Lubo1，2，CHEN Guoqing1，2，CHEN Chao1，2，. THE METHOD TO IDENTIFY CHARACTERISTIC STRESSES OF ROCK in different stages during failure process. , 2016, 35(S2): 3577-3588.
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2016, Vol. 35 
