An underground mine layout must establish the following:

• Suitable main arteries from the surface of the orebody in the form of adits, ramps, or shafts, haulage and travel ways (mine development).

• A number of working faces in the ore which gives good breaking ability under safe working conditions (stopes).

• Travelways between main arteries and the working face for the movement of men and materials and for delivery of mine services (stope development).

• Facilities for the introduction of fill or other type of support;

• Facilities for removing broken ore;

• Facilities for disposing of broken waste when required; and,

• Facilities for delivery of mine services (heating, ventilation, air conditioning, electrical, drainage)

The above requirements will be influenced by the following variables: 

1. PHYSICAL PROPERTIES OF ORE AND HOST ROCK The rock mass quality and the stress/strength relationship of the ground will determine the stope dimensions, both horizontal and vertical which will stand without support. This in turn establishes the appropriateness of the three broad stoping methods namely: 

   • Naturally Supported

   • Artificially Supported

   •  Unsupported

2. DIMENSIONS OF OREBODY The orebody strike length width (HW to FW) and height determine the maximum spans that are possible which in some cases may exceed the permissible spans based o rock mechanics considerations Longitudinal mining is progressive stoping along the strike of the orebody. Transverse stoping is perpendicular to the strike. Stope and pillar dimensions must be established.

3. DIP OF THE DEPOSIT

   The dip of the deposit will determine whether gravity transport will play a role in the selection of a mining.  The dip affects the stability of the hangingwall and whether gravity can be used to move the muck to a central drawpoint in a stope.

   In general, the dip of a deposit can be categorized as follows:

   • Flat Dip: 0-20°

   • Medium Dip: 20° - 50°

   • Steep Dip: 50° - 90°

4. GRADE OF THE DEPOSIT The grade of the deposit will influence the consideration of whether bulk, mass mining methods or more selective mining methods shall be employed. Higher grade deposits will use more selective mining methods and companies will want to achieve a very high extraction rate (recovery of pillars)

5. STRUCTURAL FEATURES Major faults dykes, foliation, jointing may influence the location of stopes and pillars and the sizing thereof. Structural features can influence stability of stopes and dilution.

6. PROXIMITY OF OTHER OREBODIES & OPENINGS How to mine one orebody or lens with respect to and adjacent orebody. The mining method selected needs to take into account the presence of nearby openings. Mining of the orebody can influence the stability of nearby mine infrastructure. The sequence of mine extraction should maximize recovery of the ore and minimize effects on infrastructure.

Mining en-echelon ore deposits

7. GROUND SURFACE EFFECTS 

• Restriction of mine subsidence (i.e. lakes and towns above) 

• Land Reclamation requirements 

• Waste and tailings disposal 

• Water discharge requirements

• Climate, topography

LOCAL FACILITIES Labour and supplies Cheap labour does not necessarily mean low mining costs. Mining method needs to be compatible with local skills and availability of skilled labour. Availability of support materials (timber, cement, fill, tailings)