Study on characteristic strength anisotropy of layered chlorite schist under uniaxial compression
HUANG Shuling,ZHONG Pengju,DING Xiuli
(Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Yangtze River Scientific Research Institute,Wuhan,Hubei 430010,China)
Abstract:The theory of traditional crack strain model is mainly based on isotropic body. It has obvious limitations to obtain the characteristic strength of layered rock mass by using this method. In order to study the characteristic strength of layered rock mass,based on the transversely isotropic theory,a transversely isotropic crack strain method is proposed to solve the characteristic strength of layered rock mass. Combined with the uniaxial compression test of chlorite schist,the deformation and failure law of chlorite schist and the characteristic strength characteristics such as closure strength,crack initiation strength,damage strength and peak strength are obtained, and the relationship between these characteristic strength and peak strength,as well as their anisotropic characteristics are analyzed. The results show that the ratio of closure strength to peak strength is in the range of 0.1–0.3,that of crack initiation strength to peak strength is in the range of 0.3–0.5,and that of damage strength to peak strength is in the range of 0.8–1.0. The closure strength,crack initiation strength,damage strength and peak strength of chlorite schist first decrease and then increase with the increase of the angle between loading direction and bedding plane. The anisotropy of crack damage strength and peak strength is between 3 and 4 with moderate anisotropy,and the crack closing strength and initiation strength is between 4 and 5,with high anisotropy.
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