New Models for Rock Joints and Interfaces

Two new developments and refinements in the modeling of rock structures are presented: a new model for axisymmetric interfaces, such as found in footing designs, and a new model which describes the dilatant effects of rock joints, such as encountered in underground caverns and reinforced rock slopes. The two new models were incorporated into a finite element program and test-case analyses were performed. The results indicate that the use of the new models can lead to more accurate estimates of footing settlements, to more economical designs of rock reinforcement, and to safer analysis of rock structures. The new dilatant joint model provides a refined estimate of joint opening and closing, and thus can also be applied to the analysis of hard rock hydraulics, in which flow is very sensitive to fracture aperture.