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Presentation on TSLs
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A Review of Application and Benefits of
Thin Spray-On Liners for Underground
Rock Support in South African Mines
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
8th South African Young Geotechnical
Engineers’ ConferenceCultivating the Future of Geotechnics
2
Introduction
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
Budget
Planned return on
investment
Safety
Business aim of mining
operations
(Stacey, 2001; 2009)
3
Introduction - continued
Potvin et al., 2001
• 90% of rockfall injuries involve rocks smaller than one metric tonne.
Lacerda, 2004
• In USA metal mines in 1996, small rocks weighing 11-kg or less were responsible for 65% of all reported injuries and fatalities.
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
Mining roof topElectricity
2%
Machinery
4%
S/W
Installation
5%
Rallbound
Equipment
10%
Trackless
Mobile
Machinery
16%
General
18%
Fall of
Ground
35%
Other
7%
Explosives
3%
(Web
ber
-Yo
ung
man
& V
an W
yk
, 2
00
9)
4
Introduction - continued
http://miningandconstruction.com/construct
ion/behind-the-gray-walls-the-art-of-
shotcreting-2485/
http://www.tensarcorp.com/Applicati
ons/Mining/mining-roof-and-wall-
support#
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
5
TSLs - Definition
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
(Ferreira, 2012) (Sudbury Mining Solutions Journal, July 2012)
6
TSLs – History and Background
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
7
TSLs – Composition, Properties & Type
Reactive or Non-reactive
Polymer based
Water basedPolyurethane/
Polyurea
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
Polymer base and Mixture type
8
Support Mechanism/Analysis of TSLs
Adhesion Tensiona)
Extent of de-
bonding
Adhesion
failureb)
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
Shear failure
fracture
zone
depth
fabric forces
tendon forces
tendon spacing
contributory areacontributory area
(Kuij
per
s et
al.
, 2004)
9
Application of TSLs in Mines
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
DescriptionRock Mass Rating
(%)
TSL Thickness
(mm)Bolting pattern1
Development drift (walls)45 - 65
2 - 31.8 m x 1.5 m2
>65 1.8 m x 1.5 m3
Development drift (roof or
back)
45 - 653 - 4
1.8 m x 1.1 m4
>65 1.8 m x 1.3 m4
Production headings (lower
wall)
45 - 65
2 - 3
1.8 m x 1.5 m5
>65 Boltless or spot bolting5
Production headings (roof
and back)
45 - 653 - 4 1.8 m or 2.4 m x 1.1 m4
>65
Note:1Mechanical bolts.
2Bolting after every two rounds of advance.3Indefinitely delayed with bi-annual audits.
4Install before or immediately after liner.5Installation can be delayed.
Tentative application guidelines for TSLs
(Esp
ley
etal
,1999)
10
Benefits from use of TSLs in SA Mines
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
Reduction in Fatalities
Increased Productivity
Effective Cover against Weathering
Flexible and
Elastic
Rapid Curing Times
Reduced Material Handling
11
Benefits – Product Comparisons (cost, application and time)
(Fer
reir
a, 2
012)
Description Shotcrete
(± 25mm)
KT 2C
(± 5mm) 3m2
KT White
(± 5mm) 3m2
KT Grey
(± 5mm) 3m2
KT Fast
(± 5mm) 3m2
Approximate ex
factory product
cost per m2
R85 R95 R85 R65 R85
Approximate
dedicated labour
cost per m2
R125 R55 R55 R55 R55
*Approximate
Total cost per m2 R210 R150 R140 R120 R140
ReboundPoor (lots of
material)Hardly any Hardly any Hardly any Hardly any
Bags per m2
Kg per m2
3.5
88
0.33
8.35
0.33
8.35
0.33
8.35
0.33
8.35
Ease of Application Cumbersome Easy Easy Easy Easy**Time to cover 45
m2 (conventional
application)
150 Minutes 55 Minutes 55 Minutes 55 Minutes 55 Minutes
Equipment Large Small Small Small Small
Interference with
development cycleHigh Minimal Minimal Minimal Minimal
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
12
Benefits – Early Age Properties Comparison
(Lac
erda,
2004)
Elapsed TimeNon-Reactive TSL Fiber Reinforced Shotcrete
MPa PSI MPa PSI
Bond Strength
1 : 15 hr : min 0.30 44
2 : 30 hr : min 0.40 58
3 : 45 hr : min 0.50 73
5 : 00 hr : min 0.55 80
6 : 00 hr : min 0.60 87
8 : 00 hr : min 0.2 29
12 : 00 hr : min 0.3 42
24 : 00 hr : min 0.5 71
25 : 00 hr : min 1.20 174
40 : 00 hr : min 1.50 218
7 days 2.00 290
28 days 1.7 239
Tensile Strength
5 hours 1.5 218
8 hours 1.0 145
24 hours 2.0 290 1.7 247
7 days 2.2 312
28 days 2.3 328
6 weeks 4.0 580
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
13
Benefits – Reduction in Fatalities
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
Relation between injuries and TSLs usage in South African
Mines (1998 – 2002)
0
200
400
600
0 20 40 60 80 100
Inju
ries
(T
ota
l co
un
ts)
TSL usage (Percentage)
(Adam
s, 2
002)
14
Conclusion
Five attributes of Innovation
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
UptakeRelative
Advantage
Compatibility
Complexity
Trialibility
Observability
(Rogers, 2003)
15
Conclusion
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
Knowledge
Persuasion
Decision
Implementation
Confirmation
Five stages of innovation process
(Rogers, 2003)
THANKS
16
Jjuuko Samuel
Department of Civil Engineering
University of Cape Town
smljju001@myuct.ac.za
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