Tunnelling ’91, London, England, Institution of Mining & Metallurgy, 14–18 April 1991
Authors: M. P. Hardy, A. M. Richardson, M. Lin, and J. F. T. Agapito (AAI)
In recent years, numerical methods have gained a measure of acceptance in design of underground openings, not as a means of supplanting traditional methods, but as an aid to engineering judgement to be used in conjunction with traditional methods. The use of efficient pre- and post-processors make these tools user friendly, encouraging investigations of the influence of varying material properties and loading conditions. The design studies presented here were performed using the two-dimensional finite-element method (FEM) implemented in the JAC code. This code provides a number of nonlinear rock models suitable for modeling jointed and yielding rock.
This paper presents two case histories from mining involving decline (inclined tunnel) and shaft design. One of these projects was designed and constructed in the early 1980s when numerical methods were more cumbersome and not as commonly used in design as now. The original analysis of deformation for jointed rock was reanalyzed for this paper using more complete models, with feedback from construction and subsequent operations providing insight into the adequacy of the design. The second project is in the final design stage.