Mechanical Anchors and Rebar Rock Bolts
2
Contents
Introduction ..................................................................................................................3
Mechanical Anchors ......................................................................................................4
Resin Rock Bolts ...........................................................................................................6
SN-Anchors ..................................................................................................................8
DYWIDAG THREADBAR®...........................................................................................11
Accessories ................................................................................................................12
Further Information .....................................................................................................13
Order Information SN-Anchors ...................................................................................14
Introduction
Anchors and rock bolts, which are
commonly assigned the general
term ”rock bolts”, are used for rock
reinforcement in Mining and Tunneling.
Rock bolts limit the loosening of
blocks out of the rock mass and shear
displacements. Furthermore, the
frictional force between individual rock
layers is increased.
GEWI® Mining Anchors and Mechanical
Anchors Type ALWAG are wellestablished systems with variable anchor
lengths. The maximum load-bearing
capacity of these mechanical anchors is
mainly determined by the stability of the
borehole (ground characteristics), the
amount of the pre-tensioning, and the
design of the expansion shell.
Anchors with a variable anchor length
enable pre-tensioning and thus an active
force transmission.
Rock bolts such as SN-Anchors or
the DYWIDAG THREADBAR® are fully
grouted over the whole length and are
usually installed untensioned.
Generally, this does not apply to resin
rock bolts, which can be actively pretensioned using resin cartridges with
different curing times.
Which rock bolt system is the best one
to use depends on a variety of factors,
which have to be considered in each
individual case. DYWIDAG-Systems
International has longtime experience in
the development, production and supply
of mechanical anchors and rock bolts.
3
Mechanical Anchors
Fields of Application
■■ Systematic anchoring in underground
Mining and Tunneling
■■ Doweling of rock layers in the hanging
wall
■■ Utility hangers
Main Advantages
■■ Simple handling and optimized
installation time
■■ Immediate loading-bearing capacity
■■ Field-proven and reliable anchors
■■ Unproblematic installation in
aquiferous boreholes
■■ Optimized ratio of anchor force
vs. borehole diameter
■■ Continuous threaded GEWI® anchor
bars allow flexible length adjustments
and posterior extension on site
■■ Expansion sleeves are available for
different borehole diameters
■■ The GEWI® Mining Anchor is approved
for underground application by the
Regional Government Arnsberg,
Dep. 6 Mining and Energy in NRW,
Germany
System Components GEWI® Mining Anchors
■■ Steel expansion shell
■Different versions available on request
■■ Anchor plate
■Flat plate with conical through-hole
■■ Anchor shaft
■Highly ductile GEWI® anchor steel
with continuous clock-wise coarse
thread
■Individual delivery lengths on
agreement
■■ Anchor nut
■Constructed as one-sided convex
hexagonal nut, self-locking nut, or
domed nut
Steel expansion shell
Anchor shaft
Anchor plate
4
Anchor nut
Mechanical Anchors
Specifications GEWI® Mining Anchors
Characeristics / Type
Nominal diameter
Nominal weight
Nominal cross-section
Yield stress 1)
Tensile stress 1)
Ultimate load 2)
Ultimate elongation A5 1)
Nut version 3)
Borehole diameter 4)
Approval file No. 5)
Unit
[mm]
[kg/m]
[mm2]
[N/mm2]
[N/mm2]
[kN]
[%]
[–]
[mm]
[–]
KS-145
16.2
1.62
207
450
700
145
15
S, H
34 - 36
83.18.24.6-2004-9
KS-190
18
2.00
254
670
800
190
15
K
44 - 47
62.18.24.6-2008-1
KS-220
20
2.46
314
500
700
220
15
K
44 - 47
83.18.24-6-2001-9
1)Steel tendon
2)Anchor system: anchor bar, plate, and nut
3)H = hex nut, one-sided convex seat, S = stop nut, K = domed nut
4)Standard version expansion shell
5)Regional Government Arnsberg, Dep. 6 Mining and Energy in NRW, Germany
System Components Mechanical Anchors Type ALWAG
■■ Expansion shell
■Expansion shells in versions B38
and B43 available, appropriate for
borehole diameters of 38 and 43 [mm]
■■ Anchor bar
■Solid anchor bar, threaded on both
ends
■Steel grade E360 according to
EN 10025-2
■■ Plate
■Standard version: domed plate with
round hole
■■ Nut and washer
■Spherical washers and driver tools
available on request
Specifications Mechanical Anchors Type ALWAG 1)
Characteristics
Diameter
Thread designation
Cross-sectional area
Yield strength 2)
Ultimate strength 2)
Ultimate elongation A5 2)
Ultimate load 3)
Delivery lengths
■■ Other dimensions, steel grades, and
galvanized versions are available on
request
Unit
[mm]
[–]
[mm2]
[N/mm2]
[N/mm2]
[%]
[kN]
[mm]
Installation Procedure
Type
16
M18
200
360
690
11
140
500 - 6,000
1)Mechanical Anchors and expansion shells in other dimensions are available on request, all indicated
values are nominal
2)Round bar tendon
3)Mechanical Anchors with cold-rolled thread, plate, washer, and nut
■■ Drilling of an anchor borehole in
accordance with the specifications,
approx. 150 [mm] longer than the
expansion shell anchor when installed
■■ Introduction of the readily assembled
expansion shell anchor into the
borehole - the expansion shell shall fit
tight into the borehole
■■ Pre-tensioning via impact screw driver
or adequate driver tool
■■ Optional post grouting using a
factory-fitted injection hose
5
Resin Rock Bolts
Fields of Application
Main Advantages
System Components
■■ Systematic rock bolting in
underground Mining
■■ All-purpose rock bolt system installation in jointed or soft rock
■■ Increase of the load-bearing capacity
of the rock mass, especially in coal
Mining
■■ Standardized and field-proven rock
bolts
■■ Standard application for use in
combination with DYWIDAG resin
cartridges
■■ High bolting forces at short bond
lengths
■■ Rock bolt shaft
■Mining steel
■Optimized thread profile for combined
use with resin cartridges
■Pointed, with one-sided cold-rolled
thread
■■ Resistant against blasting vibrations
■■ Plate
■Domed plate, alternative compatible
versions available on request
■■ Nut
■Standard version with DYWIDAG
drive nut (shear pin nut)
■DYWIDAG OZ-Nut available on
request
■Installation spanners available on
request
Specifications
No.
1
2
3
4
5
6
7
8
9
10
11
12
Characteristics / Type 1)
Nominal diameter
Thread
Nominal cross-section anchor bar 2)
Nominal weight anchor bar 3)
Yield load anchor bar 4)
Ultimate tensile load anchor bar 4)
Yield stress anchor bar 5)
Tensile stress anchor bar 5)
Ultimate elongation anchor bar 5)
Ultimate load anchor system 6)
Wrench size nut
Delivery lengths 7)
Symbol
Da.nom
–
S0
m
Fe.nom
Fe.nom
Re.nom
Rm.nom
Agt
Fm.A.nom
SW
L
Unit
[mm]
[mm]
[mm2]
[kg/m]
[kN]
[kN]
[N/mm2]
[N/mm2]
[%]
[kN]
[mm]
[mm]
MN16-130
16
M18
210
1.67
105
134
500
640
10
130
27
600 - 1,600
MN18-210
18
M20
316
2.14
158
202
500
640
10
210
30
600 - 1,600
1) Status: 2012-08, note: all values are subject to change; other dimensions and steel grades available on request
2) Calculated from the nominal weight: S0 = 106 x m / 7,850 [kg/m3]
3) Characteristic fractile value
4) Calculated from the characteristic load value and nominal weight, rounded
5) Mining steel type DD-BAR, modulus of elasticity: 210,000 [N/mm2]
6) Nominal value ultimate system load: anchor head with cold-rolled thread, plate, and nut
7) Off-size lengths are available on request
6
MN20-230
20
M22
329
2.58
164
240
500
730
10
230
32
600 - 2,400
MN25-360
25
M27
468
3.67
234
341
500
730
10
360
41
600 - 2,400
Resin Rock Bolts
Torque Indicators
■■ Reliable indication for a correctly
installed resin rock bolt
■■ Assembly between nut and bolt plate
■■ Available for all resin rock bolt types
Corrosion Protection
■■ Corrosion protection of system
components may be provided by hot
dip galvanizing or alternative coatings
Installation Procedure
■■ Borehole drilling
■Manual or automated insertion of the
resin cartridges
■Rotary installation of the resin anchor
until the installation depth has been
reached
■■ Activation of the resin cartridge by
mixing the components
■Holding time is to be adjusted to the
applied synthetic resin cartridges or
valid installation instructions
■Tensioning of the bolt’s head by
tightening the nut
7
SN-Anchors
Fields of Application
SN-Anchors, also known as mortar
embedded concrete reinforcement
steel anchors or Store-Norfors-Anchors
(named after the first place of installation),
are used for rock reinforcement in
underground Mining and Tunneling.
For special requirements in Tunneling,
especially rock reinforcement in squeezing
ground and large displacements directly
after bolt installation, DSI also offers
SN-Anchors with ALWAGRIP special rib
geometry for an increased load-bearing
capacity.
The DYWIDAG THREADBAR® is mainly
used for special underground bolting
works as well as for underpinnings or
as utility hanger.
Main Advantages
■■ Field-proven rock bolt system
■■ Effective and standardized installation
■■ Embedding of the tension member in
grout ensures optimal bond strength
■■ Low sensitivity concerning the actual
diameter of the anchor borehole
■■ ALWAGRIP special rib geometry for
optimized bond strength available
on request
System Components
Standard rock bolt head with
plain washer and nut
Rock bolt shaft
Plate
■■ Rock bolt shaft
■Reinforcement steel B 500 B
according to DIN 488, B 550 B
according to ÖNORM B 4707 or
rock bolt steel FA 650/820
■Pointed, with cold-rolled thread at
the far end, including nut and washer
■Standard thread length approximately
120 [mm], maximum thread length
200 [mm] available on request
■Special ALWAGRIP rib geometry
for increased bond available on
recommendation
8
Washer
and nut
■■ Plate
■Default bolt plate: domed, with long
hole
■Other bolt plates in different
dimensions available on request
■■ Waher and nut
■Rock bolt head version with
hemispherical washer available
on request
■Optional free bolt length using a
shrink tube
Rock bolt head with hemispherical
washer, plain washer, and nut
SN-Anchors
Specifications
No.
1
2
3
4
5
6
7
8
9
10
11
12
Characteristics / Type 1)
Nominal diameter
Thread
Nominal cross-section anchor bar 2)
Nominal weight anchor bar 3)
Yield load anchor bar 4)
Ultimate tensile load anchor bar 4)
Yield stress anchor bar 5)
Tensile stress anchor bar 6)
Ultimate elongation anchor bar 5)
Ultimate load anchor system 7)
Wrench size nut
Delivery lengths 8)
Symbol
Da.nom
–
S0
m
Fe.nom
Fm.s.nom
Re.nom
Rm.s.nom
Agt
Fm.A.nom
SW
L
Unit
[mm]
[mm]
[mm2]
[kg/m]
[kN]
[kN]
[N/mm2]
[N/mm2]
[%]
[kN]
[mm]
[mm]
SN20-180
SN25-250
SN25-330
SN28-330
20
25
25
28
M21
M26
M26
M30
315
490
490
615
2.47
3.85
3.85
4.83
173
245
319
308
190
260
340
330
550
500
650
500
594
540
820
540
5.0
5.0
5.0
5.0
180
250
330
330
36
41
41
46
1,000 - 12,000 1,000 - 12,000 1,000 - 12,000 1,000 - 12,000
1) Status: 2012-06, note: all values are subject to change; other dimensions and steel grades available on request
2) Calculated from the nominal weight: S0 = 106 x m / 7,850 [kg/m3]
3) Characteristic fractile value
4) Calculated from the characteristic load value and nominal weight, rounded
5) Reinforcement steel B 500 B according to DIN 488, B 550 B according to ÖNORM B 4707 or rock bolt steel FA 650/820,
modulus of elasticity: 210,000 [N/mm2]
6)Calculated from the ratio Rm/Re or according to manufacturer specifications
7) Nominal value ultimate system load: anchor head with cold-rolled thread, plate, washer, and nut
8) Off-size lengths are available on request
Compatible domed plates
Characteristics / Type
Length
Wall thickness
Height
Width center boring
Length center boring
Symbol
L
s
H
D1
D2
Unit
[mm]
[mm]
[mm]
[mm]
[mm]
SN20-180
150
8
32.5
23
28
SN25-250
200
10
32.5
28
38
SN25-330
200
12
32.5
28
38
SN28-330
200
12
32.5
32
42
Installation procedure
■■ Borehole drilling
■■ Filling of the boreholes with mortar
■■ Manual insertion of SN-Anchors into
the pre-filled boreholes, fixation in
the borehole using a wedge or
similar device
■■ Curing time is to be adjusted to the
applied grout or valid installation
instructions
■■ Tensioning of the bolt’s head by
tightening the nut
9
SN-Anchors
ALWAGRIP Special Rib Geometry
■■ According to the guideline RVS 8T,
Federal Minstry for Transport,
Innovation and Technology, Austria
■■ The rib geometry of conventional
SN-Anchors is in accordance with
the regulations of concrete steel
reinforcement
■■ Ground deformations in Tunneling
usually occur immediately after the
installation of SN-Anchors, which is
why the requirements for bond strength
development differs from reinforced
concrete construction
■■ Development of ALWAGRIP special
rib geometry in accordance with
the requirements for SN-Anchors in
Tunneling, especially in squeezing
ground conditions
■■ Obtained rib area between 0.02 and 0.04
(cf. RVS 8T, Federal Ministry for Transport,
Innovation and Technology, Austria)
■■ Material characteristics of SN-Anchors
with ALWAGRIP special rib geometry
are considerably better than for similar
anchors and rock bolts with concrete
reinforcement ribbing
■■ The advantages of using a steel grade
with higher yield strength are observable
after a curing time of 12 hours
■■ Examination of the inner bond for two
different anchor steel types depending
on curing time
■■ Results of pull-out tests after
12 hours curing time, bond length
500 [mm]
250
Tension force [kN]
200
150
100
50
0
0
25
50
75
100
Displacement [mm]
Rock bolt steel Ø 25 [mm] FA 650/820 with ALWAGRIP special rib geometry
concrete rib steel Ø 25 [mm] B 500 B
10
DYWIDAG THREADBAR®
Nut
Main Advantages
Plate
■■ Optimized ratio of anchor force to
borehole diameter
■■ Continuous threaded bar allows length
adjustment and subsequent extension
on-site
■■ Wear-resistant coarse thread according
to the requirements in underground
construction
GEWI® bar
System Components
■■ GEWI® bar
■With right or left hand coarse thread
■Optional extension using couplings
■■ Double corrosion-protected version
and free length systems with jacket
tube available on request
■■ Plate
■Domed or flat
■■ Nut
■Domed or hexagonal version
■Eye bolts available on request
Specifications
Type
GEWI® - lefthand thread
GEWI® Plus right-hand
thread
Nominal diameter
[mm]
Cross-sectional
area [mm2]
Yield strength
[N/mm2]
Tensile strength
[N/mm2]
Yield load
[kN]
Ultimate load
[kN]
16
20
25
28
32
40
50
18
22
25
28
30
35
43
57.5
201
314
491
616
804
1,257
1,963
254
380
491
616
707
962
1,452
2,597
500
500
500
500
500
500
500
670
670
670
670
670
670
670
670
550
550
550
550
550
550
550
800
800
800
800
800
800
800
800
101
157
246
308
402
628
982
170
255
329
413
474
645
973
1,740
111
173
270
339
442
691
1,080
204
304
393
493
565
770
1,162
2,077
11
Accessories
Plates
■■ Standard version: domed or flat plate
■■ Steel grade S235 according to EN 10025-2
■■ Custom-specific lugs for domed plates
■■ Special plates are available on request
Length
[mm]
Width
[mm]
Wall thickness
[mm]
Version 1)
150
150
180
200
200
250
150
150
180
200
200
250
8
10
8
10
12
12
C/W
C/W
C/W
C/W
C/W
W
1)C ... cold formed calotte with oval breakout (long hole);
W ... warm formed calotte with round breakout (round hole)
12
Accessories
Custom-specific accessories available on request
■■ Cable and bar truss systems
■■ Sliding nuts for anchors and rock bolts
■■ Angle compensation discs and plates
■■ Load indicators
■■ Spacers
■■ Dollies and spanners
■■ System components in galvanized or duplex-coated versions
■■ Mortar-Mixing pump and injection adaptors
■■ Pull testing equipment for all types of anchors and rock bolts
Further References
■■ DIN 21521-1,2: Rock bolts for mining
and tunnel support
■■ DSI’s installation guidelines for
anchors and rock bolts
■■ DIN 21521-1,2: Rock bolts for mining
and tunnelling
■■ EN 14490: Implementation of works in
foundation engineering – soil nailing
■■ Federal Ministry of Transportation,
Innovation and Technology (Ed.):
Guidelines and regulations for road
building: RVS 8T – Technical contract
conditions tunneling. 2004-08
■■ Payer, M., Maydl, P.:
Inspection report – Pull-out tests of
SN-Anchors. Order-No.: 77.645/08,
Test date: 2008-04-22 - 2008-06-13.
Technical Examination and Research
Center for stability and material tests,
Graz Technical University. Graz, Austria,
2008
■■ Schubert, W. (Ed.):
Recommendation – Fully mortared
rock bolts (SN-Anchors) – Special Rib
Geometry and requirements for the
mortar; Institute of Rock Mechanics
and Tunnelling; Graz, Austria, 1997-07
■■ Blümel, M.:
Bearing load of rock bolts in squeezing
rock mass, Proceedings ISRM
International Symposium EUROCK ’96
Turin, Italy, Balkema Rotterdam, 1996
■■ Blümel, M.; Schweiger, H.F.; Golser, H.:
Effect of Rib Geometry on the
Mechanical Behaviour of Grouted
Rock Bolts, Proc. of World Tunnel
Congress ’97, 23rd General Assembly
of the International Tunnelling Ass.,
Vienna, Austria, 1997
13
Order Information SN-Anchors
Article Description
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
SN-Anchor
14
SN20-180, L = 2,000 [mm]
SN20-180, L = 3,000 [mm]
SN20-180, L = 4,000 [mm]
SN20-180, L = 6,000 [mm]
SN20-180, L = 8,000 [mm]
Domed plate SN20, 150x150x08-023 [mm]
Domed plate SN20, 200x200x10-023 [mm]
Nut M21, SW 36 [mm]
Coupling M21-M21
Hemispherical washer M21, d. 23 [mm]
SN25-250, L = 2,000 [mm]
SN25-250, L = 3,000 [mm]
SN25-250, L = 4,000 [mm]
SN25-250, L = 6,000 [mm]
SN25-250, L = 8,000 [mm]
SN25-330, L = 2,000 [mm], ALWAGRIP
SN25-330, L = 3,000 [mm], ALWAGRIP
SN25-330, L = 4,000 [mm], ALWAGRIP
SN25-330, L = 6,000 [mm], ALWAGRIP
SN25-330, L = 8,000 [mm], ALWAGRIP
Nut M26, SW 41 [mm]
Coupling M26-M26, L = 90 [mm]
Hemispherical washer M26, d. 26 [mm]
Domed plate SN25, 150x150x08-028 [mm]
Domed plate SN25, 150x150x10-028 [mm]
Domed plate SN25, 200x200x10-028 [mm]
Domed plate SN25, 200x200x12-028 [mm]
SN28-330, L = 2,000 [mm]
SN28-330, L = 3,000 [mm]
SN28-330, L = 4,000 [mm]
SN28-330, L = 6,000 [mm]
SN28-330, L = 8,000 [mm]
Nut M30, SW 46 [mm]
Coupling M30-M30
Hemispherical washer M30, d. 30 [mm]
Domed plate SN28, 200x200x10-032 [mm]
Domed plate SN28, 200x200x12-032 [mm]
Article No.
201310181020
201310181030
201310181040
201310181060
201310181080
201340012008
201340013010
201320011036
201330011000
201350010000
201910251020
201910251030
201910251040
201910251060
201910251080
201910332020
201910332030
201910332040
201910332060
201910332080
201920011041
201930011000
201950010000
201940012008
201940012010
201940013010
201940013012
202110331020
202110331030
202110331040
202110331060
202110331080
202120011046
202130011000
202150010000
202140013010
202140013012
15
Austria
DSI Austria
DYWIDAG-Systems International GmbH
Alfred-Wagner-Strasse 1
4061 Pasching/Linz, Austria
Phone +43-7229-610 49 0
Fax +43-7229-610 49 80
E-mail alwag@dywidag-systems.at
www.alwag.com
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”ALWAG” (AM 952/79), ”AT” (AM 6138/2003),
”AT-SYSTEM” (AM 6139/2003),
”DYWI®” (4197869), ”LSC” (AM 4326/2008),
”OMEGA-BOLT®” (3258282),
”POWER SET” (AM 6163/2002), and
”TUBESPILE” (AM 4328/2008) are registered
trademarks of DYWIDAG-Systems International GmbH.
”Combi Coat®” and ”CT-Bolt” are trademarks
of Vik Ørsta AS.
DYWIDAG-Systems International GmbH
is a partner of Vik Ørsta AS.
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04343-1/12.12-web he
Please note:
This brochure serves basic information
purposes only. Technical data and information
provided herein shall be considered
non-binding and may be subject to change
without notice. We do not assume any liability
for losses or damages attributed to the use
of this technical data and any improper
use of our products. Should you require
further information on particular products,
please do not hesitate to contact us.
U n i t e d A r a b E m i r at e s