Numerical simulation of prefabricated cracked rock under uniaxial compression experiment

WANG Yunfei; MA Yongchao; DONG He

doi:10.16186/j.cnki.1673-9787.2021100058

Abstract：In order to study the effects of prefabricated cracks on the mechanical properties,acoustic emis-sion and energy evolution of rock under uniaxial compression,the mechanical parameters of PFC2D numeri-cal simulation model were inverse performed in laboratory experiments,and then the effects of different dip angles and lengths of prefabricated cracks on rock properties were analyzed on the basis of numerical simu-lation.The experimental results show that the peak stress and peak strain of rock increase with the increase of prefabricated crack angle,and the elastic modulus and deformation modulus also increase with the in-crease of prefabricated crack angle.However,when the length increased,the peak stress,peak strain,elastic modulus and deformation modulus decreased continuously.When the prefabricated crack dip angle was 0°,15°,30°,45°,the microcrack count fluctuates greatly,and when the prefabricated crack dip angle was 60°,75°,90°,the microcrack count was stable.At the same time,when the dip angle of prefabricated crack was 0°,15°,30°,45°,60°,the airfoil crack is the main crack growth,while when the dip angle of prefabricated crack is 75°,90°,there is no airfoil crack,but a large number of micro-cracks appear on the rock mass.Un-der the action of axial stress,these micro-cracks are gradually connected,resulting in shear failure.When the prefabricated crack angle is0°,15°,30°,45°,the internal damage of rock appears earlier than that of 60°,75°,90°,and the elastic storage limit increases with the increase of the prefabricated crack angle.