单轴压缩下层状岩体的各项异性研究

摘要

Beddings have important influence on rock mass strength and anisotropy characteristics.In order to analyze the effects of bedding dip and density on the strength anisotropy of rock mass,the variation law of model strength and elastic modulus with bedding inclination and density is obtained by uniaxial compression test of similar model standard specimen.The failure mode of the specimen is analyzed deeply,and the experimental results are verified by theoretical calculation.The results show that the strength of the rock mass increases with the increase of the inclination of the bedding plane,and it reaches the minimum value of about60°.Variation of the elastic modulus with the bedding planes of the rock tilt angle is generally 45° cut-off point,approximately in a "V" changes.The effect of bedding density on the strength,elastic modulus,failure mechanism and anisotropy ratio of rock mass is small.The anisotropy ratio of the specimen with the in-terlayer spacing of 10 mm is 4.72,and the anisotropy ratio of the sample spacing is 20 mm is 4.46,which belongs to the high heterosexual level.The failure mechanism of the specimen is mainly shear slip,tensile failure,and their combina-tion.%层理对岩体强度和各向异性特征都有重要影响,为了详细的研究层理间距和倾角对岩体强度各向异性特征的影响,通过对类层状岩体标准试样的单轴压缩试验,得出了试样的强度和弹性模量随层理间距 、倾角的变化规律,并深入分析了试样的破坏形态,最后通过理论计算对试验结果进行了验证.研究结果表明:岩体强度随层理面倾角的增加近似呈"U"型变化的规律,并在60°左右达到最小值;岩体的弹性模量随层理面倾角的变化规律总体上是以45°为分界点,近似呈"V"型变化;岩体的强度 、弹性模量 、破坏机制和各向异性比受层理面间距的影响均较小,层理间距为10 mm的试样各向异性比为4.72,层理间距为20 mm的试样各向异性比为4.46,均属于高各项异性水平;试样破坏机理主要是剪切滑移和张拉破坏,以及两者的组合.