Analysis of fracture evolution process of single fractured rock mass based on uniaxial compression
In order to investigate the influences of fissure inclination on the rupture evolution process of fissured rock body,this paper carried out uniaxial compression experiments on rock bodies with different fissure inclinations.The digital scattering and acoustic emission methods were adopted as the observation means to investigate the rupture evolution process of rock bodies containing different fissure inclinations.And the evolution law of the surface of the different single-fissure rock bodies and their internal cracks were analyzed as well.The results show that the deformation and destruction process of the fractured rock body is similar to that of the intact rock body,which is manifested in four stages:original fracture compaction,elastic deformation,plastic deformation and destruction;with the increase of fracture inclination,the peak stress,i.e.,the compressive strength,shows a tendency of decreasing first and then increasing.When the cracks on the surface of the rock body are in the stable expansion stage,the cracks firstly start cracking along the end of the prefabricated cracks,and then the cracks expand,penetrate,and form macroscopic cracks until the macroscopic cracks develop to the unstable expansion stage.When the inclination angle of the cracks is 0°,the rock body shows a more obvious tensile damage.The rocks show a combination of shear-dominated damage when the inclination angles of the cracks are 30°,45°,and 60°.The rock body shows a combination of shear-dominated damage when the inclination angle of the cracks is 90°,and the rock body undergoes elastic deformation.When the fissure inclination angle is 90°,the rock body undergoes tensile damage.Through the acoustic emission observation,the evolution of cracks inside the single-fracture rock body is observed.In the initial period of acoustic emission,there are a large number of pores inside the rock body.With the increase of stress,the primary pores are gradually compressed and dense,and the collected ringer counts are relatively small.With the increase of deformation,the rock body enters into the stage of elastic deformation,and the rock body produces micro-cracks inside the rock body,the ringer counts become more and tend to be stabilized compared with the initial period.When it enters into the stage of plastic deformation,i.e.,cracks,the rock body enters into the stage of plastic deformation,i.e.,cracks.When entering the plastic deformation stage,i.e.,the stable crack expansion stage,the cracks start to crack along the prefabricated fissures on the surface of the rock body and continue to develop until the cracks penetrate through,and the rock body forms a macroscopic rupture and reaches the destruction stage.With the change of crack inclination angle,the internal crack extension situation produces differences,resulting in the plastic deformation stage of single-fracture rock body coming time shows a tendency of decreasing and then increasing.
single fissurecrack evolutiondigital speckleacoustic emissionuniaxial compression
万方数据
维普
