Physical and particle flow modeling of jointed rock block behavior under uniaxial loading

Laboratory experiments and numerical simulations, using Particle Flow Code (PFC3D), were performed to study the behavior of jointed blocks of model ma terial under uniaxial loading. The effect of joint geometry parameters on t he uniaxial compressive strength of jointed blocks was investigated and thi s paper presents the results of the experiments and numerical simulations. The fracture tensor component in a given direction is used to quantify the combined directional effect of joint geometry parameters including joint de nsity, orientation and size distributions, and the number of joint sets. Th e variation of the uniaxial compressive strength of the jointed blocks of t he model material with the fracture tensor component was investigated. Both the laboratory experiments and the numerical simulations showed that the u niaxial block strength decreases in a nonlinear manner with increasing valu es of the fracture tensor component. It was observed that joint geometry co nfiguration controls the mode of failure of the jointed blocks and three mo des of failure were identified, namely (a) tensile splitting through the in tact material, (b) failure by sliding along the joint plane and/or by displ acement normal to the joint plane and, (c) mixed mode failure involving bot h the failure mechanisms in (a) and (b). It has also been shown that with c areful parameter calibration procedures, PFC3D could be used to model the s trength behavior of jointed blocks of rock. (C) 2001 Elsevier Science Ltd. All rights reserved.