Mechanical response and failure mechanism of inclined rough jointed rock under true triaxial compression loading
Authors: LIU Han-xiang, JING Hong-wen, YUAN Yong, YIN Qian, WEN Fan, LI Bo
Rock-like specimens containing a joint with different inclination angles and roughness were prepared using 3D printing technology. Then, true triaxial compression loading experiments were conducted on those jointed specimens. The increase in roughness leads to an increase in the axial strength and peak strain. With the increasing inclination angle, the axial strength initially decreases from 30° to 60° and then increases from 60° to 90°. While the peak strain first rises from 30° to 45° and then declines from 45° to 90°. The variation in failure mode results from differences in lateral stress on the joints under different strike directions. Specimens with joint strike parallel to the intermediate principal stress predominantly showed matrix or matrix-joint mixed shear failure, whereas those parallel to the minimum principal stress exhibited matrix shear failure. The analysis results of acoustic emission signals indicate the crack number and shear crack percentage increase with the increasing roughness and first decrease (30° to 60°), then increase (60° to 90°) with the increasing inclination angle. The research results can provide some guidance for the design and support of underground engineering with jointed surrounding rock.
