The slab failure of rock mass is one of the common destruction phenomena in underground engineering. Based upon equivalent rock mass (ERM) technique

the fracture (parallel to the free surface) and rock block are represented by the smooth-joint model and bonded-particle model

respectively. The strength

crack distribution

crack initiation and evolution

and slab failure formation mechanism of fractured rock mass under one side restriction (OSR) compression are studied by comparing experimental results and numerical modelling. With the increase in the number of fracture

the OSR compressive strength of rock mass exhibits linear decreasing. Under OSR loading

five types of cracks generated in rock mass can be identified. The type-Ⅰ and type-Ⅱ (shear) cracks are caused by the loading end effect

while the type-Ⅲ

type-Ⅳ and type-Ⅴ cracks are caused by slab failure of rock mass. In the process of slab failure

type-Ⅴ cracks which causes rock mass spalling at the unconfined boundary first occurs. Then type-Ⅳ cracks result in the propagation of original fractures generate. Finally

the type-Ⅲ cracks generate

which indicates that the slab failure phenomenon is developing towards the interior of rock mass. In various specimens under OSR loading

the relationship between the acoustic emission (AE) quantities and crack magnitude approximates Gaussian function distribution.