EXPERIMENTAL VALIDATION OF NONLINEAR STRENGTH PROPERTY OF ROCK UNDER HIGH GEOSTRESS
WANG Bin1，ZHU Jiebing1，WU Aiqing1，LIU Xiaohong1，2
(1. Key Laboratory of Geotechnical and Engineering of Ministry of Water Resources，Yangtze River Scientific Research Institute， Wuhan，Hubei 430010，China；2. Faculty of Engineering，China University of Geosciences，Wuhan，Hubei 430074，China)
Abstract：The strength characteristics of deep rock mass exhibit distinctly nonlinear response to excavation. Based on triaxial compressive tests and unloading confining pressure tests results under high stress in laboratory，the behaving nonlinear strength property is validated. Moreover，the nonlinear strength parameters¢ change laws by loading and unloading paths of rock failure are brought into research. The quadratic parabola，hypobola，and power types of envelope functions are employed to present nonlinear strength characteristics；and the results reveal that the power type of Mohr criterion can favourably describe the strength property of rock under high geostress in loading path as well as unloading path. The triaxial unloading failure strength is usually less than that under triaxial compressive strength at low stress level，and reversed at higher stress level. According to relationship of internal friction angle with equivalent normal stress，the intrinsic friction angle is not constant，which takes on power functional type of nonlinear characteristics and attenuates gradually to angle of π/4.
汪斌，朱杰兵，邬爱清，刘小红，. 高应力下岩石非线性强度特性的试验验证 [J]. 岩石力学与工程学报, 2010, 29(03): 542-548.
WANG Bin1，ZHU Jiebing1，WU Aiqing1，LIU Xiaohong1，2. EXPERIMENTAL VALIDATION OF NONLINEAR STRENGTH PROPERTY OF ROCK UNDER HIGH GEOSTRESS. , 2010, 29(03): 542-548.
