Evaluation of the limits of empirical stability graph method (SGM) for Swedish underground mines

Purpose and goal:

The objectives of the proposed project expressed in detail are to: 1) evaluate the limits of empirical SGM used for stope dimensioning by using numerical technique; 2) develop three-dimensional numerical modelling methodology to reconcile field observation; 3) improve the current stope design method with the aid of numerical analysis based on collection of case histories from different rock masses in Swedish underground mines; and 4) develop a project plan for the subsequent full-scale project.

Expected results and effects:

The expected results from this project are: i) improved understanding of the influential factors on stope stability and limitations of the current SGM; ii) an innovative methodology for assessing empirical SGM based on 3DEC numerical modelling analyses; and iii) a developed project plan for the subsequent full-scale project. In the end, the following KPIs defined in the Strategic Research and Innovation Roadmap (2022) for 2030 and beyond will be addressed: no fatalities and minimised Lost Time Injuries (LTI), improved ore recovery and minimum dilution, and minimised waste.

Approach and implementation:

The study included: literature review, data collection, numerical methodology development, model calibration, data analysis and evaluation of results. The project comprised various activities and the research work was divided into four work packages.

Since the mining companies were participating in this project, the results had been discussed with them during the project workshops. They will be implemented in Garpenberg and Zinkgruvan mines after the project. The results will also be published in Eurock2024 conference and communicated with experts worldwide.