ABSTRACT
Rock media contain different kinds of discontinueties such as cracks, joints, etc. under various loads, stress components concentrate on crack tips and lead to crack propagation, coalescence and breakage of rock mass. Different numerical and experimental studies are carried out to investigate the mechanical behavior of fractured rock medium. Various experimental research are carried out on different kind of materials, including Plaster of Paris (Lajtai 1980), sandstones (Petit & Barquins 1988), marble (Huang et al. 1990, Wong & Einstein 2006), gypsum (Reyes & Einstein 1991, Shen 1993, Bobet & Einstein 1998, Sagong & Bobet 2002) and artificial sandstone (Wong & Chau 1998, 2001). In different studies, crack propagation and coalescence are investigated on specimens with two open/closed flaws (Shen 1993, Bobet 1997), three and 16 open flaws (Sagong & Bobet 2002) and three closed flaws (Wong et al. 2001, Park & Bobet 2007).
