Numerical Study of the Mechanical Behavior of Nonpersistent Jointed Rock Masses

Abstract

Estimating the mechanical properties of nonpersistent jointed rock masses is one of the most challenging problems in practical rock engineering due to the complex interaction of rock joints and intact-rock bridges. In this paper, the effect of joint geometrical parameters of nonpersistent rock mass on uniaxial compressive strength (UCS) and the deformation modulus was studied by using the discrete-element particle flow code PFC3D. In this numerical approach, the intact material is represented by an assembly of spherical particles bonded together at their contact points, and the joint interface is explicitly simulated by slip surfaces that are applied at contacts between the particles lying on the opposite sides of the joint interface. The failure process is simulated by the breakage of bonds between particles. A previous study of the authors has shown that this approach is capable of reproducing the mechanical behavior of nonpersistent jointed rock masses by a comparative study against physical experiments. In this study, the effect of joint geometrical parameters, including joint-orientation angle, spacing, persistency degree, step angle, and aperture, on the UCS