A simplified approach to directly consider intact rock anisotropy inHoekeBrown failure criterion

Many rock types have naturally occurring inherent anisotropic planes, such as bedding planes, foliation,or flow structures. Such characteristic induces directional features and anisotropy in rocks＇ strength anddeformational properties. The HoekeBrown （HeB） failure criterion is an empirical strength criterionwidely applied to rock mechanics and engineering. A direct modification to HeB failure criterion toaccount for rock anisotropy is considered as the base of the research. Such modification introduced a newdefinition of the anisotropy as direct parameter named the anisotropic parameter （Kb）. However, thecomputation of this parameter takes much experimental work and cannot be calculated in a simple way.The aim of this paper is to study the trend of the relation between the degree of anisotropy （Rc） and theminimum value of anisotropic parameter （Kmin）, and to predict the Kmin directly from the uniaxialcompression tests instead of triaxial tests, and also to decrease the amount of experimental work.
2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

A simplified approach to directly consider intact rock anisotropy in Hoek–Brown failure criterion

Many rock types have naturally occurring inherent anisotropic planes, such as bedding planes, foliation, or flow structures. Such characteristic induces directional features and anisotropy in rocks' strength and deformational properties. The Hoek–Brown (H–B) failure criterion is an empirical strength criterion widely applied to rock mechanics and engineering. A direct modification to H–B failure criterion to account for rock anisotropy is considered as the base of the research. Such modification introduced a new definition of the anisotropy as direct parameter named the anisotropic parameter (K_β). However, the computation of this parameter takes much experimental work and cannot be calculated in a simple way. The aim of this paper is to study the trend of the relation between the degree of anisotropy (R_c) and the minimum value of anisotropic parameter (K_min), and to predict the K_min directly from the uniaxial compression tests instead of triaxial tests, and also to decrease the amount of experimental work.