Crack initiation and failure development in bimrocks using digital image correlation under dynamic load

摘要: Abstract Bimrocks are a kind of rocks in which blocks randomly distributed matrix. Despite their wide distribution nature, significant effects on the failure rock structures such as slopes, mines and tunnels have been neglected. behave differently than any other types they contain mix (of different strength, size volume matrix) matrix physical mechanical characteristics). The interaction between complex making study deformation cracking difficult under loading. Therefore it is great importance to fully understand behaviour micro level. Dynamic loading adds more complexity this demand comprehensive assessment. This investigates crack initiation bimrocks experimental dynamic impact analyses via digital image correlation (DIC) method. Split Hopkinson pressure bar (SHPB) combined with high speed camera record videos entire for analysis purposes. Three sets various block dimensions (small, medium large) prepared loaded assess behaviour. Also specimens dynamically one low (150 1/s) (300 1/s) impacts better evaluate rocks. DIC results show that large exhibit considerable tortuosity path an extensive irregular develops. having sized degree also seen, but much less blocks. small almost no influence pattern similar intact rock. Moreover, shear block-matrix contacts inclined regard direction then tensile cracks initiate from cracks. observed Small only cracking. Interestingly, carry lowest load, while highest peak load due presences weak contacts. Under some broken breakage observed. comparison quasi-static tests reveals rate has effect pattern, sizes play role.