1) Material Weights
Excavation is the act of removing, moving, and depositing the veneer like surface of the
earth's outermost crust. The material excavated may be in the solid or semi-solid state,
that is, rock; in the weathered state, usually a mixture of rock and earth; or in the loose
state, earth.
The weight of (1yd3) or (1m3) of material in its undisturbed natural condition, before it
is being broken or blasted is called bank weight, stated in (lb./yd 3 bank).
The weight of (1yd3) or (1m3) of material after it has been blasted or loosened in
another way and once it ends up in the bucket of a loading machine or in the body of a
dump truck is called lose weight, stated in (lb./yd3 loose).
Completely dry material which consists of mainly the same size particles will neither
swell nor shrink (this includes all kinds of gravel with approximately the same size
granulation). Table (1-1) shows us different types of rocks and their weight
characteristics.
Figure 1-1
Any material which is being loosened by either blasting or other methods will grow in
volume. (Figure 1-1). This volume increase is stated in % or as a factor. It’s called
percentage of swell (% swell), or swell factor (Fs).
The amount of swell depends on:
1. The kind of material
2. The way of how it was loosened
3. The size of the single particles after the material has been loosened.
Mine Machinery
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Eng. Saleh Ajarmeh
Percentage of swell (% swell), or swell factor (Fs), is really the ratio between bank and
loose material and it is expressed mathematically:
1-1
 bank unit weight 
 loose volume 
Swell %  
1  100%  
1  100%
 loose unit weight 
 bank volume 
1-2
Swell factor( Fs ) 
loose dry unit weight
100 %

bank dry unit weight 100 %  Swell %
The ratio between nominal volume and actual volume of a bucket or the body of a
dump truck, given as percentage of nominal volume, is called fill factor (Ff).
Load Factor (Fl) or Bucket Factor (Fb), Converts the nominal payload volume of a
dump truck (in loose yd3 or m3) into the effective loaded volume (in bank yd3 or m3).
DIN 24095 defines the load factor as:
Fl  Fs  F f
1-3
Payload
The payload of the hauling equipment me be expressed either gravimetrically or
volumetrically. Volumetric capacity can be stated as struck measure or in terms of: 1. Loose cubic yard (Lyd3)
2. Bank cubic yard (Byd3)
Struck measure means that the hauling equipment is filled with material just to the end
of the side boards. While heaped measure allow to increase the payload to a certain
level as shown in figure (1-2).
Figure 1-2
Manufacturer’s specification sheets will list both struck and heaped capacities for the
specified truck. Struck capacity (material measured straight across the top of the body).
Heaped capacity (material measured based on a 2:1 slope above hauler bodies).
The payload capacity of a hauling unit is often stated by the manufacturer in terms of
the volume of loose material that the unit can hold, assuming that the material is heaped
in some specified angle of repose.
A gravimetric capacity would represent the safe operational weight that the axles and
structural frame of the machine were designed to handle.
Mine Machinery
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Eng. Saleh Ajarmeh
Table (1-1) Materials weights and swell factors
Material
Bank weight (lb./yd3) Loose weight (lb./yd3) Swell % Swell factor
Andesite
4300
3100
39
0.72
Anorthosite
4600
3300
39
0.72
Basalt
5100
3350
52
0.66
Bauxite
3250
2450
33
0.75
Brucite
3900
2800
39
0.72
Caliche
3800
2450
55
0.65
Carnotite
3700
2750
35
0.74
Clay
2800
2300
65
0.82
Coal
2700
2000
35
0.74
Diabase
5000
3600
39
0.72
Diorite
4900
3500
40
0.71
Dolomite
4850
3100
56
0.64
Earth
2800
2400
58
0.85
Gabbro
5000
3600
39
0.72
Granite
4600
2800
64
0.61
Gravel
3300
2950
12
0.89
Gypsum
4700
2700
74
0.57
Hematite
4800
4080
18
0.85
Limonite
4500
3200
40
0.71
Magnetite
5400
4590
18
0.85
Pyrite
5100
4335
18
0.85
Siderite
5800
4100
41
0.71
Taconite
8500
4850
75
0.57
Limestone
4400
2600
69
0.59
Mica Schist
4600
3300
39
0.72
Norite
4900
3500
40
0.71
Nepheline Syenite
4300
3100
39
0.72
Peridotite
5400
3900
39
0.72
Porphyry
4300
3100
39
0.72
Quarts
4500
3200
40
0.71
Quartzite
4300
3100
39
0.72
Rhyolite
4200
3000
40
0.71
Rock Salt
3900
2800
39
0.72
Salt rock
3900
2500
56
0.65
Sand
3300
2950
12
0.89
Sandstone
3800
2400
58
0.63
Shale
4300
3200
34
0.75
Slate
4600
3500
31
0.77
Talk
4600
3300
39
0.72
Topsoil
2300
1600
44
0.69
Trap Rock
4725
3375
40
0.71
Tuff
3900
2800
39
0.72
Mine Machinery
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Eng. Saleh Ajarmeh