3D Numerical modeling of artificial ground freezing in mining engineering
Résumé
For decades, Artificial Ground Freezing (AGF) technique has been used for waterproofing and strengthening soils and soft rocks. However, the resulting pore pressure build up may endanger the stability of adjacent structures located inside and outside the frozen area. Consequently, the use of this technique requires the development of numerical tools that not only allow to predict the extent of the frozen zone around the cooling sources, but also to anticipate the ground movements and the site stability problems. On the basis of the Theory of Porous Media, a thermo-hydro-mechanical coupled model is derived and validated against field data collected in the Cigar Lake underground mine, comprising temperature and tunnel displacement measurements. Three-dimensional finite-element simulations of the Cigar Lake mine have allowed a better understanding of the freezing process and its impacts, in a challenging mining environment.