【摘要】 为了研究层状千枚岩的力学特性与各向异性特征，开展了不同层理倾角与不同围压下的千枚岩力学试验。对比分析了千枚岩试样强度、变形、脆性与破坏模式等各向异性特征。结果表明：（1）随着层理倾角β增加，岩样的强度、变形特征曲线形状呈U型；随围压增加，岩样强度及塑性增强，各向异性度逐渐减弱稳定。（2）采用多种强度准则描述岩样强度各向异性，其中Saeidi准则和改进Ramamurthy准则能很好地预测岩样在不同层理倾角下的抗压强度。（3）基于岩样峰前应力-应变曲线与能量特征提出了综合脆性评价指标，在层理倾角β=45°左右时，岩样脆性指标较低，更易发生剪切滑移破坏，得出脆性下降顺序为：沿层理面拉伸劈裂>穿层理面拉伸劈裂>沿层理面剪切>穿层理面剪切。（4）千枚岩的破坏模式与层理倾角和围压有关，单轴条件下，岩样劈裂破坏后易形成复杂裂纹网络；高围压下，岩样破裂后多形成单一的沿层理面或贯穿多层理面的剪切破坏。更多还原

【Abstract】 In order to study the mechanical properties and anisotropy characteristics of layered phyllite, rock mechanical tests of phyllite were conducted under different bedding inclinations and different confining pressures. The anisotropic mechanical properties in strength, deformation, brittleness and failure modes of phyllite samples were comparatively analyzed. Some findings were as follows.(1) As the bedding inclination β increases, the strength and deformation characteristic curve of the rock sample is U-shaped;and the strength and plasticity increase, the anisotropy gradually decreases and stabilizes with the increase of confining pressure.(2)The anisotropic Saeidi criterion and the modified Ramamurthy criterion can well predict the failure strength of rock specimens under different bedding inclinations.(3) A comprehensive brittleness index of phyllite samples at different bedding inclination under different confining pressures is proposed based on the stress–strain curve characteristic and energy equilibrium. The brittleness index is lower, and the shear failure is more likely to occur when the bedding inclination β is about 45°. The relationship between brittleness and the failure mode is revealed, and the decreasing order of brittleness is concluded as follows: tensile splitting along bedding plane > tensile splitting through bedding plane > shear along bedding plane > shear through bedding plane.(4) The failure modes of phyllite are related to the bedding inclinations and confining pressures. Under uniaxial compression conditions, complex networks of fractures are formed easily after splitting failure of rock samples; and under high confining pressure conditions, a single shear failure plane is generally formed along the bedding plane or through multiple planes after rock failure.更多还原