Study on the influence of joint distribution on dynamic mechanical characteristics and failure mode of cross-jointed rock mass
s:In order to reveal the influence mechanism of intersecting joints on the dynamic strength and failure mode of rock mass,the dynamic mechanical behavior of rock mass with intersecting joints under different joint distribution forms was studied,considering the angle,penetration degree of intersecting joints,penetration degree of main joints and strain rate,etc.Influenced by the parameters,the split Hopkinson pressure bar(SHPB)impact test was carried out,and a high-speed camera was set to record the failure process of the sample in real time.The dynamic mechanical properties,energy dissipation and crack initiation-failure laws of the cross-jointed rock mass were analyzed.The research results show that:(1)with the increase of joint angle and(main)joint penetration,the dynamic compressive strength and elastic modulus of cross-jointed rock mass show a downward trend,and there is an obvious rate correlation.(2)The main cracks of the sample always occur along the main joint surface,and change from wing cracks to wing cracks and coplanar cracks with the increase of penetration.The crack initiation and connection modes are different in different joint distribution forms.The main three failure modes are splitting tensile failure along the loading direction,tensile failure along the prefabricated joint surface and tensile-shear composite failure along the prefabricated joint surface.(3)With the increase of the penetration and included angle of the main joints,the length of the joint surface of the incident wave front increases,the transmission energy through the joint surface decreases,and the damage degree of the sample increases,resulting in a sudden increase of the dissipated energy.
rock mechanicscross-joint rocksplit Hopkinson pressure bar(SHPB)energy dissipationtailure mode
万方数据
维普
