2
Parts of a bench
Geometrical Considerations
Cumulative frequency
distribution of measured
bench face angles (Call, 1986).
3
Section through a working bench.
Functioning of catch benches.
Geometrical Considerations
4
Double benches at final pit limits. Catch bench geometry (Call, 1986).
Typical catch bench design dimensions (Call, 1986).Bench height Impact zone Berm height Berm width Minimum bench width
(m)153045
(m)3.54.55
(m)1.523
(m)45.58
(m)7.51013
Geometrical Considerations
5
Safety berms at bench edge
Geometrical Considerations
6
Height of reach as a
function of bucket
size.
Geometrical Considerations
7
Example orebody geometry.
Ramp access for the example orebody.
Blast design for
the ramp
excavation.
Geometrical Considerations
8
Shovel Working Range
9
Minimum width drop cut
geometry with shovel
alternating from side to side.
Geometrical Considerations
10
Minimum width drop cut
geometry with shovel
alternating from side to side.
Geometrical Considerations
11
Isometric view of the ramp in
waste approaching the
orebody.
Diagrammatic
representation of the
expanding mining front.
Geometrical Considerations
12
Dropcut / ramp placement in ore. Expansion of the mining front.
Geometrical Considerations
13
Plan view of an actual pit bottom
Showing drop cut and mining
Expansion (McWilliams, 1959).
Geometrical Considerations
14
Extension of the current
Ramp close to the pit wall
(McWilliams, 1959).
Geometrical Considerations
15
Creating initial access /
benches.
Shovel cut sequence when
initiating benching in a hilly
terrain (Nichols, 1956).Sidehill cut with a shovel.
Geometrical Considerations
16
Detailed steps in the
development of a
new production level.
Geometrical Considerations
17
Parallel cut
with drive by.
Geometrical Considerations
18
Parallel cut with
the double
spotting of trucks.
Geometrical Considerations
19
Parallel cut with
the single spotting
of trucks.
Geometrical Considerations
20
Time sequence
showing shovel
loading with single
spotting.
Geometrical Considerations
22
Time sequence
showing shovel
loading with double
spotting.
Geometrical Considerations
23
(Continued).
Geometrical Considerations
24
Geometrical Considerations
(Continued).
25
Section and plan views through a working bench.
Simplified presentation of a safety berm.
Geometrical Considerations
26
Initial geometry for the push back example.
Cut mining from bench 1.
Cut mining from bench 2.
Geometrical Considerations
27
Overall slope angle.
Safety bench geometry
showing bench face angle.
Geometrical Considerations
28
Overall slope angle with ramp included.
Interramp slope angles.
Geometrical Considerations
29
Overall slope angle with
Working bench included.
Interramp angles associated with
the working bench.
Geometrical Considerations
30
Overall slope angle with
one working bench an a ramp section.
Interramp slope angles for a slope containing
a working bench and a ramp.
Geometrical Considerations
31
Overall slope angle for a
slope containing two
working benches.
Geometrical Considerations
32
Slopes for each working group.
Geometrical Considerations
33
Final overall
pit slope.
Geometrical Considerations
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