节理面对千枚岩物理力学性状的影响

节理面对岩体物理力学性状具有显著影响。以千枚岩为例,开展常规三轴压缩试验,讨论节理面与最大主应力夹角、围压对岩石破坏模式的影响。结果表明:1)节理面与最大主应力夹角在5°~45°,破坏模式有张拉-剪切复合型破坏、横交节理面剪切与沿节理面滑动的复合型破坏以及沿节理面间的剪切滑动破坏三种;2)随节理面与最大主应力夹角增大,峰值强度逐渐降低,破坏模式发生由复合型向单一型的转变;3)千枚岩变形、强度参数具有明显"夹角效应",节理面与最大主应力夹角对弹性模量和黏聚力影响较为显著;4)围压增大会降低岩石节理面的力学效应。

EFFECTS OF JOINT PLANE ON PHYSICAL AND MECHANICAL PROPERTIES OF PHYLLITE

Joint plane of rocks have a significant impacts on their physical and mechanical properties. The conventional triaxial compression test of natural phyllite was carried out to research the effect of the included angle between the maximum principal stress,joint plane,and confining pressure on the rock deformation-failure mode. The test results showed: 1) There were three deformation-failure modes with the included angle being in the range of 5° to45°: tension-shear composite failure,shear-slide composite failure across,and along the joint plane,and shear failure only along the joint plane. 2) The peak strength of the rock gradually decreased and the failure mode changed from the composite type to single type with increase of included angle. 3) The deformation and strength parameters of phyllite had obvious "angle effect",especially on elastic modulus and cohesion. 4) The increase of confining pressure would weaken the mechanical effect of rock joint plane.