In the process of coal mining in Southwest China,the fracture development of overlying rock is significant,the mining disturbance is strong,and the control of surrounding rock is difficult.In order to study the failure mechanism of fractured rock and improve the control effect of surrounding rock in southwest mining area,uniaxial compression tests combined with DIC technology were used to study the influences of fracture dip angle and fracture number on the mechanical properties,surface deformation field and fracture propagation path of rock-like specimens.The results show that during the change period of fracture dip angle from 0° and 90° to 45°,the decrease degree of uniaxial compressive strength of rock increases from 12.47％and 16.66％to 28.83％respectively.The average peak strength of single-fracture specimen,double-fracture specimen and three-fracture specimen is 80.24％,69.07％and 56.94％of the peak strength of complete specimen.Single-fracture specimens often exhibit cracks propagation along the fracture tip under unidirectional stress,while multi-fracture specimens exhibit cracks parallel to the loading direction.When the fracture dip angle of single-fracture specimens is 45° and 60°,the maximum principal strain of the specimens exceeds that of the complete specimens.In multi-fracture specimens,only double-transverse-fracture specimens exhibit this phenomenon.This research result can provide a theoretical basis for controlling the stability of surrounding rocks in coal mines in Southwest China.
关键词
单向应力/裂隙演化/预制裂隙/破坏特征/最大主应变
Key words
Unidirectional stress/Fracture evolution/Prefabricated fracture/Failure characteristics/The maximum principal strain
维普
万方数据