Failure mode and strength anisotropic characteristic of stratified rock mass under uniaxial compressive situation

Abstract

A stratified rock mass model was founded by FLAC^3D. The failure mode and anisotropic characteristic of strength for stratified rock mass were analyzed. The analysis results show that the numerical simulation can visually reflect the failure modes of rock samples under different inclination angles β of structural plane. The stiffness of rock sample before peak strength changes in the compressive procedure. With the increase of β, the compressive strength σ_c of rock sample decreases firstly and then increases; when β is in the range of 20°–30° and 80°–90°, σ_c has the largest sensitivity to β; while β falls in the range of 30°–70°, σ_c varies little. When ϕ_j<β<90° (β_j is friction angle of structure plane), the results obtained from numerical simulation and theoretical analysis are in almost the same values; while β⩽ ϕ_j or β=90°, they are in great different values. The results obtained from theoretical analysis are obvious larger than those from numerical simulation; and the results from numerical simulation can reflect the difference of compressive strength of rock samples for the two situations of β⩾ ϕ_j and β=90°, which is in more accordance with the real situation.

Keywords

stratified rock mass / failure mode / strength / anisotropic characteristic / numerical analysis

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