Cave mining design methodology for use in challenging geomechanics environments

摘要

Underground cave mining design tends to rely upon empirical and numerical models, neither of which are able to close the engineering design loop. Such circumstances, mean that it is very difficult to analyse with certainty, the causes of significant problems that can arise from time to time. Widespread collapses and damaging mining-induced seismicity, have occurred, for example, within the El Teniente mine, and are examples of cave mining problems that appear to have been without resolution. Further, fundamental and relevant engineering design issues tend to be lost in a swathe of other issues, which have only minor importance, in comparison to the major concern in cave mining - that of long-term stability and productivity of the production complex. Cave mining design methodology put forward in this paper is based upon the fundamental precepts that: a detailed and in-depth knowledge and understanding of the geomechanics mechanisms involved in the response of the rock mass to the creation of excavations by mining is essential, selection of alternative design components is based upon quantitative risk analyses integrated within project cash flows, and successful implementation of mining designs requires that operators follow method-specific mining tactics. Practical examples are outlined to illustrate the process.