单轴压缩下裂隙灰岩宏细观力学特性试验研究OA

In order to study the influence of fracture inclination angle on the mechanical properties and macroscopic and microscopic failure mechanisms of rocks,this article first conducted uniaxial compression tests on fractured limestone samples with different inclination angles to study their macroscopic mechanical failure characteristics.Then,a corresponding numerical calculation model was constructed using a particle flow platform to reveal the micro crack propagation law of fractured limestone with different inclination angles.The results showed that as the inclination angle of the crack increased,the peak strength of the crack specimen showed a"V"-shaped trend of first decreasing and then increasing,while the elastic modulus showed a linear change.The minimum peak strength was observed at a crack inclination angle of 15°,which decreased by 57.3%compared to the intact specimen.During the loading process,the number of cracks shows a trend of first increasing,then decreasing and increasing again with the increase of the inclination Angle.The mesoscopic crack occurrence events are classified into three stages:the dormant period,the active period and the surging period,and the cumulative crack occurrence curves respectively show a gentle trend,an upward trend and a steep trend.Mesoscopic cracks first originate from the tip of the prefabricated crack and gradually extend and penetrate towards both ends.When the inclination Angle is less than 45°,the crack propagation direction is at an acute angle to the crack direction.When the inclination angle is less than 45°,the crack propagation direction forms an acute angle with the fracture direction.When the fracture inclination angle is greater than 45°,the angle between the mesoscopic crack propagation penetration direction and the fracture inclination angle direction is close to 90°.