Experimental analysis on behaviors of blast-induced crack propagation in different notched borehole orientations

A digital dynamic caustic experimental system was used to study the effect of different notched orientations to the blast-induced main crack propagation behavior.Five different notched orientations were studied on how they influence blast-induced crack propagation and interaction.The result proves that the difference of included angle has obvious effect on the blast-induced main crack propagation trajectory.The larger the included angle of notches orientations, the larger the crack propagation velocity in the medium term of blast-induced main crack propagation.When the included angle of notched orientations are 90°, 135ånd 180°, the second peak values in the blast-induced main crack tip will appear.