具有孔边裂纹的岩石厚壁筒试件的破裂特征

FRACTURE CHARATERISTICS OF THICK-WALLED CYLINDER ROCK SPECIMEN WITH PORE EDGE CRACK

用五种应力途径对由五种岩石制备的孔边有予裂纹的厚壁筒试件进行实验,研究上述条件下岩石的破裂特征。结果表明:对含径向并贯穿轴向裂纹的试件,其破裂沿裂纹方向,为典型的张开型破裂;含与定直径成45°角并贯穿轴向裂纹的试件,破裂亦呈张开型,其裂面始于裂纹前缘,但却折转约45°角与定直径近于平行;中心含与轴向成45°角的椭圆裂纹试件的破裂,仍沿裂纹面方向,为张开型与滑开型的复合破裂。

Five loading paths are adopted to test thick-walled cylindrical specimens with pre-notched cracks on their internal pore edges which made by five kinds of rocks and to study the fracture characteristics of rock under such conditions. The results show that. to the specimen having a radial crack and going all the way through the axial direction, the fracture is a typical stretch fracture, because it cracks in the direction of its crackle; to the specimen having a crack at 45° along the axial direction, the fracture is also of stretching type and its face starts at the leading edge of the crack but turns 45° to the near parallel direction and parallel to the fixed diameter; and to the specimen having elliptical crack at its waist at 45° angle to axial direction, the fracture goes along the direction of the crack face and belong to the hybrid fracture of types with stretch slip.