Study On The Similar Model Test Of Fissure Propagation Under Uniaxial Compression

Rock is a complicated geological medium that usually contains defects such asjoints, fissures, faults, These defects strongly affect the rock failure mechanism.Moreover, some problems，such as the evolvement and fracture pattern of initiation，propagation and coalescence from some primary flaws in rock mass，and the influenceon rock strength and rock mechanics character，are always focused by the researchers ofgeology field and rock mechanics field．On the study of rock containing fissures, theexperimental study is generally carried on by prefabricating fissures in rock specimens.Many researchers have done a lot of work about the specimens containing two and threefissures, however, the specimens containing four or more fissures has not been studiedcomprehensively. In this paper, an experimental study of rock-like specimens containingfour penetrated fissures under uniaxial compression has been done, the main work issummarized as follows:①According to experimental need and condition, a reasonable testing scheme isdetermined. Meanwhile, specimen size is determined and corresponding moulds aremade, moreover, the specimens contain three fissure angles,300,450,600, respectively,and three front end distances,0mm,10mm,20mm, respectively.②The specimens are loaded with INSTRON1342servo testing machine underuniaxial compression, axial stress and axial strain are obtain, meanwhile, the axialstress-strain curves are drawn.③When the specimens are loaded, the HG-100K high-speed digital videocamera system is used to take images, and the whole process of crack initiation,propagation and coalescence is recorded.④The crack propagation characteristics of specimens containing fissures arestudied, and the modes of crack initiation and coalescence are analysed, meanwhile, theinfluence of fissure angle and front end distance on crack initiation and coalescence areanalysed.⑤The mechanical property of specimen containing different fissure angle arestudied, the influence of fissure angle on the axial stress-strain curves, peak intensity,peak strain and elastic modulus are analysed.⑥The mechanical property of specimen containing different fissure front enddistance are studied, the influence of fissure front end distance on the axial stress-strain curves, peak intensity, peak strain and elastic modulus are analysed.