Mine Design or Mine Plan ?
1. Mine design :
a. Geometry and location of mine workings and related features
b. Stability, safety, efficient operation
2. Mine plan :
a. A sequence of mine designs at various stages of the operation
b. Ability to meet financial and other goals
3. Sometimes used interchangeably
Sample Mine Design Parameters
1. Operating and remnant bench widths and heights
a. Equipment and technology employed
2. Slopes between benches
a. Overall operating slope
b. Slope stability considerations
3. Road widths and grades
a. Haulage productivity and safety
b. Minimization of volumes to be excavated
4. Pushback (cutback) widths
Sample Pit Design
Two Major Mine Design Components
1. THE PIT(s)
a. Slopes : benches, berms, other
b. Haul roads
2. THE DUMP(s)
a. Type, location, lift height, other
b. Environment protection
* Slides, water pollution, other
Classification of Pit Slopes
After Hoek
1. Unimportant slopes
a. Little consideration of stability is required
b. Shallow orebody with favorable geology and climate
2. Average slopes
a. Approximate analysis is adequate
b. Reasonable geology and climate
3. Critical slopes
a. Detailed geological and groundwater study
b. Followed by detailed stability analysis
“Average” slope?
Pit Wall Safety
Factors :
1. falling or rolling loose material
2. failure of individual benches
3. slope failure involving the stability of the whole pit slope
Precautions :
1. proper design of mine bench heights and slope angles
2. proper width of catch benches
3. regular and efficient scaling of loose rock
4. proper design and maintenance of overall slope angles
5. efficient slope drainage
6. elimination of damage due to blasting