The demand for increased production, safety and resource recovery has put pressure on the coal industry to find better practices while mining through fault zones. One of the processes used to reduce the likelihood of face instability (fall events) and weighting events on the production coal face is to consolidate the strata around the fault using grouting techniques. Since grouting techniques are being used more frequently in practice the industry requires a greater understanding of the subject to evaluate when to grout and the extent of grouting that is required.
This thesis reviews the current grouting techniques used in Australian longwall mines and in other fields including tunneling, civil engineering and dam stability. The research conducted includes an analysis of Moranbah North Coal mine where data was collected for a comparative analysis of theoretical grouting assessment and empirical results. This thesis also identified what analysis and calculations can be utilised to review and predict design of the consolidation method of a fault. The systematic approach recommended enables understanding of what the grouting program requires, how it will be implemented and possibly what the expected outcomes of grouting will be.
The grouting methodology was also investigated the conventional method of grouting and the ‘Grout Intensity Number’ (GIN) method. A systematic approach to grouting is recommended using a combination of the conventional and GIN method that enables a better representation of the grouting program conducted and increases the ability to manage the task more effectively. This new methodology suggests typical ranges of grout volumes for given pressure constraints. The combined GIN and conventional grouting methodology has been presented for use in consolidation analysis.