Modeling Lamination of Shale Rock Failure Pattern in PFC۲D

There are two types of rock discontinuity, inherent discontinuities such as lamination and structural discontinuities such as joints. Inherent discontinuity leads to anisotropic mechanical behavior. However, it is a challenge to model their mechanical behavior under the influence of stress. Inherent discontinuities caused by depositional changes and characterized by regularly aligned weak planes. Shale rock is characterized by laminated texture, in which the thin layers (lamina) break into parallel layers less than one centimeter thick. In this study, point load (PL) tests were carried out on the anisotropic laminated shale rock. Based on these tests, a numerical model for the delamination of shale rock is developed by using the distinct element method (DEM) in ۲D-Particle Flow Code©. The aim of this study is to validate the numerical model by pattern failure mechanism (PFM) to evaluate the mechanical behavior of laminated shale rock. In current numerical modeling, the smooth joint model (SJM) has been applied for the estimation of inherent anisotropic discontinuity. SJM is one of the compatible and appropriate constitutive models, which can play a significant role in crack initiation and propagation process in hydraulic fracturing of shale gas, CO۲ sequestration, open pit, and underground mining slope stability.