The Tetron spherical bearing S3 SPHERICAL ‘S3’ Bearings are the most advanced and sophisticated support bearings available, providing complete structural freedom in rotation and horizontal sliding. All Freyssinet bearings are manufactured in accordance with BS 5400: Section 9.2:1983.
Material specifications Tetron ‘S3’ bases and rockers use maintenance-free aluminium alloy. Sliding plates are made of structural steel, faced with high quality stainless steel. Sliding surfaces are lined with pure PTFE to BS 6564. Pins for side restraints are special spring steel with minimum yield strength 1100 N/mm². All permanently exposed steel parts are fully corrosion protected. Several different treatments are available, full technical data on request. Full details of material specifications are available on request.
Design
Contact stress
Sliding friction The friction coefficient for PTFE is not constant but decreases with increasing direct stress. Tetron bearings are permanently lubricated to reduce the static coefficient of friction.
The average base contact stress of the bearings illustrated approaches 17.5N/mm². Direct contact between the aluminium parts of the bearings and dissimilar metals must be avoided.
Lateral restraint It is emphasised that only one S3F bearing at a support should be provided to resist a full transverse force, because it is not possible to position two bearings in a rigid structure to guarantee that such a force will be shared equally between them. Also, adequate vertical load must be present to ensure stability. We recommend consultation with our Engineer. High rotation ± 3º (0.052 radians) in any plan e. More than adequate for most structural purposes. Removeability All bearings are designed to be removable with minimum jacking of the structure.
*’Tetron’ is a registered trademark. 2
Installation General
Base Fixings
Top Fixings
In a bearing that is free sliding in all An ‘E’ type bearing is free sliding in all For similar reasons, top fixings must be directions (i.e. the S3E range) positive directions with a low coefficient of friction, provided for all bearings (optional for the fixing to the main structure may not be so that theoretically the bases do not ‘E’ type). required if the bearing is always require mechanical fixing, (figure 1) but subjected to adequate vertical loading. see notes above. All other types of A completed precast concrete structure Horizontal movement will occur on the bearings can resist horizontal loading and may be lowered on to a skim or mortar on plane of least resistance which is, of so their bases should be fixed. the top of the bearing, to eliminate soffit course, the bearing sliding surface. irregularities. The mortar mix needs Nevertheless, in some cases it is prudent There are several ways of achieving this. careful control to ensure that it is not to provide fixings to guard against The fixing bolts and sockets can be totally squeezed out by the weight of the displacement during installation, impact, attached to the bearing base with a superstructure, which must be supported vibration and accidental unloading. rubber washer between the socket and until it has set. The fixing sockets for the base. It is then possible to cast in the top of the bearing should be ready cast Most cases of bearing malfunction are fixings and grout the bearing in one into the soffit, but this requires accurate attributable to faulty installation and operation. The bearing may be supported casting, using a jig drilled mould insert to almost all bearing damage occurs during on temporary packs, aligned, levelled and match the bolting arrangement in the installation or even earlier during handling a chemical resin grout poured around the bearing. Alternatively, the sockets may and storage. Careless handling on site sockets and under the bearing (Fig 2) be replaced by a single plate, cast in flush and the ingress of dirt can easily lead to using some simple shuttering. The fixings with the soffit, and tapped to receive the abnormally high frictional resistance. should not be over-tightened when the bearing fixing bolts. Tetron ‘S’ bearings are normally delivered grout has set; otherwise the bearing may in a condition to discourage unnecessary be distorted due to compression in the Where a concrete superstructure is cast dismantling and temporary bolts are used washers. Nevertheless, rubber washers in-situ, the bearing top plates, with dowels to connect together the upper and lower must be used to prevent the sockets can be built into the soffit shuttering. The parts of the bearings. These temporary carrying vertical loading. This is the area around the mould cut out must be fixings, as well as excluding dirt during preferred method of fixing and ensures carefully sealed to ensure that concrete installation, prevent accidental relative bearing removeability. does not leak into the working parts of the displacement between the parts of the bearing during placing, and all sliding bearings but they must be removed In special cases, a large recess can be plates must be propped to prevent them before the bearings are called upon to left in the abutment into which the bearing distorting under the weight of wet slide or rotate. However, they are not base is placed bodily, bedded upon and concrete. structural fixings and should be surrounded with cement/sand or epoxy supplemented for example by wedges resin mortar (see fig.3). The recess must Great care must be exercised to ensure during installation. be correctly reinforced on all sides. This that ‘F’ lateral restraint bearings are method does not meet the removeability correctly orientated. Bearings should be clearly identified and requirement. Freyssinet can help by marking them with such details as type and location when Clearly sockets provide the easiest castrequested. Bearings should be in fixings with removal in view, for all transported and unloaded carefully and types of bearing. Notes then stored under cover in clean, dry Bearings should not be dismantled on conditions until required. site because the effects of dirt on the sliding and rotating surfaces are highly As much preparatory work as possible deleterious. should be c arried out before bringing a bearing to its actual location. The seating In all cases the transit bolts must be should be level and this usually removed after the mortar has set and necessitates the use of a mortar bedding Figure 1 before the bearing is called upon to rotate composed of sand and either cement, or slide. polyester resin or epoxy resin, with a cube crushing strength of at least 35N/mm².
Figure 2
Figure 3 3
Tetron S3T Fixed
(Fixed in all directions, free to rotate in all directions.)
* Assuming vm = 1.2 ‘Working stress’ design (kN)
A
B
C
D
E
F
G
H
Max. Load Vertical
Max. Load Horizontal
Vertical
Horizontal
Vertical *
Horizontal
S3T 70
70
400
215
340
145
230
177
M12
700
65
700
65
900
110
S3T 150
100
475
305
410
235
305
240
M20
1500
150
1500
150
2000
210
S3T 250
105
510
360
435
280
375
297
M20
2500
250
2500
250
3000
300
S3T 300
115
570
400
490
310
420
336
M24
3000
280
3000
280
3800
400
S3T 350
130
600
440
515
335
465
364
M24
3500
300
3500
300
4500
500
S3T 400
140
660
485
565
355
500
396
M30
4000
360
4000
360
5000
600
S3T 500
145
685
510
585
375
535
417
M30
5000
450
5000
450
6300
650
S3T 600
155
760
565
640
430
600
463
M30
6000
500
6000
500
7500
710
S3T 750
180
930
660
795
500
705
548
M30
7500
600
7500
600
9500
900
S3T 1000
195
970
710
830
535
755
583
M30
10000
750
10000
750
12500
1100
S3T 1200
215
1080
790
925
595
840
654
M30
12000
900
12000
900
15000
1300
Bearing type
1. 2.
Principal dimensions (mm)
BS.5400:Section 9.1 Design load effects (kN) Serviceability Limit State Ultimate Limit State
Bearing type column indicates maximum vertical design load in tonnes for ‘Working stress’ design or BS.5400 Serviceability Limit state. Larger bearings are available – details on request. 4
Tetron S3F Sliding Guided
(Sliding, guided in one direction, free to rotate in all directions.)
`
* Assuming vm = 1.2
‘Working stress’ design (kN) Bearing type
Principal dimensions (mm)
BS.5400:Section 9.1 Design load effects (kN) Serviceability Limit State
Ultimate Limit State
Max. Load Vertical
Max. Load Horizontal
Vertical
Horizontal
Vertical *
Horizontal
700
65
700
65
900
110
M20
1500
150
1500
150
2000
210
M20
2500
250
2500
250
3000
300
336
M24
3000
280
3000
280
3800
400
465
364
M24
3500
300
3500
300
4500
500
460
500
396
M24
4000
360
4000
360
5000
600
660
470
535
417
M30
5000
450
5000
450
6300
650
724
525
600
463
M30
6000
500
6000
500
7500
710
720
832
620
705
548
M30
7500
600
7500
600
9500
900
770
881
670
755
583
M30
10000
750
10000
750
12500
1100
S3F 70
A 100
B 351
C 270
D 286
E 190
F 230
G 177
H M12
S3F 150
130
497
360
432
280
305
240
S3F 250
135
541
420
476
340
375
297
S3F 300
145
636
460
546
360
420
S3F 350
155
680
480
590
400
S3F 400
170
718
540
628
S3F 500
175
750
570
S3F 600
190
814
625
S3F 750
225
922
S3F 1000
240
971
S3F 1200 265 1055 860 965 760 840 654 M30 12000 900 12000 900 15000 1300 Basic bearing as tabulated is for zero movement, and is specified typically as S3F250/00. For additional movements increase C and E dimensions by 100mm per increment when bearing is described in a code, e.g. S3F 250/10 (movement in cm). 2. Bearing type column – indicates maximum vertical design load in tonnes for ‘Working stress’ design or BS.5400 Serviceability Limit State. 3. Larger bearings available – details on request. 1.
Tetron S3F Sliding Guided
(Sliding, guided in one direction, free to rotate in all directions.)
`
* Assuming vm = 1.2
‘Working stress’ design (kN) Bearing type
Principal dimensions (mm)
Max. Load Vertical
Max. Load Horizontal
BS.5400:Section 9.1 Design load effects (kN) Serviceability Limit State Vertical
Horizontal
Ultimate Limit State Vertical *
Horizontal
S3F 70
A 100
B 351
C 270
D 286
E 190
F 230
G 177
H M12
700
65
700
65
900
110
S3F 150
130
497
360
432
280
305
240
M20
1500
150
1500
150
2000
210
S3F 250
135
541
420
476
340
375
297
M20
2500
250
2500
250
3000
300
S3F 300
145
636
460
546
360
420
336
M24
3000
280
3000
280
3800
400
S3F 350
155
680
480
590
400
465
364
M24
3500
300
3500
300
4500
500
S3F 400
170
718
540
628
460
500
396
M24
4000
360
4000
360
5000
600
S3F 500
175
750
570
660
470
535
417
M30
5000
450
5000
450
6300
650
S3F 600
190
814
625
724
525
600
463
M30
6000
500
6000
500
7500
710
S3F 750
225
922
720
832
620
705
548
M30
7500
600
7500
600
9500
900
S3F 1000
240
971
770
881
670
755
583
M30
10000
750
10000
750
12500
1100
S3F 1200 265 1055 860 965 760 840 654 M30 12000 900 12000 900 15000 1300 1. Basic bearing as tabulated is for zero movement, and is specified typically as S3F250/00. For additional movements increase C and E dimensions by 100mm per increment when bearing is described in a code, e.g. S3F 250/10 (movement in cm). 2. Bearing type column – indicates maximum vertical design load in tonnes for ‘Working stress’ design or BS.5400 Serviceability Limit State. 3. Larger bearings available – details on request. 4. ±3º (0.052 radians) rotation in any plane. 5
Tetron S3E Free Sliding
(Free sliding in all directions, free to rotate in all directions.)
* Assuming vm = 1.2 ‘Working stress’ design (kN) Bearing type
1. 2.
3. 4.
Principal dimensions (mm)
Max. Load Vertical
BS.5400:Section 9.1 Design load effects (kN) Serviceability Limit State Vertical
Ultimate Limit State Vertical *
A
B
C
D
E
F
G
H
S3E 70
90
340
265
280
205
230
177
M12
700
700
900
S3E 150
109
395
325
335
265
305
240
M20
1500
1500
2000
S3E 250
120
485
385
410
315
375
297
M20
2500
2500
3000
S3E 300
125
555
420
495
360
420
336
M20
3000
3000
3800
S3E 350
140
620
460
560
400
465
364
M20
3500
3500
4500
S3E 400
145
675
490
615
430
500
396
M20
4000
4000
5000
S3E 500
150
710
520
650
460
535
417
M20
5000
5000
6300
S3E 600
160
740
575
680
515
600
463
M20
6000
6000
7500
S3E 750
190
815
660
755
600
705
548
M20
7500
7500
9500
S3E 1000
200
910
720
840
650
755
583
M20
10000
10000
12500
800 S3E 1200 220 1000 925 725 840 654 M20 12000 12000 15000 Basic bearing as tabulated is for zero movement in both the principal and transverse directions and is specified typically as S3E 150/0000. For additional movement C and E increase by 100mm per increment of principal movement and/or B and D increase by 100mm per increment of transverse movement when bearing is described in a code. e.g. BEARING TRANSVERSE MOVEMENT (cm)
PRINCIPAL MOVEMENT (cm) Bearing type column indicates maximum vertical design load in tonnes for ‘Working stress’ design or BS.5400 Serviceability Limit State. Larger bearings are available – details on request.
Tetron S3E Free Sliding
(Free sliding in all directions, free to rotate in all directions.)
* Assuming vm = 1.2 ‘Working stress’ design (kN) Bearing type
1. 2.
3. 4. 5.
Principal dimensions (mm)
BS.5400:Section 9.1 Design load effects (kN)
Max. Load Vertical
Serviceability Limit State Vertical
Ultimate Limit State Vertical *
A
B
C
D
E
F
G
H
S3E 70
90
340
265
280
205
230
177
M12
700
700
900
S3E 150
109
395
325
335
265
305
240
M20
1500
1500
2000
S3E 250
120
485
385
410
315
375
297
M20
2500
2500
3000
S3E 300
125
555
420
495
360
420
336
M20
3000
3000
3800
S3E 350
140
620
460
560
400
465
364
M20
3500
3500
4500
S3E 400
145
675
490
615
430
500
396
M20
4000
4000
5000
S3E 500
150
710
520
650
460
535
417
M20
5000
5000
6300
S3E 600
160
740
575
680
515
600
463
M20
6000
6000
7500
S3E 750
190
815
660
755
600
705
548
M20
7500
7500
9500
S3E 1000
200
910
720
840
650
755
583
M20
10000
10000
12500
800 S3E 1200 220 1000 925 725 840 654 M20 12000 12000 15000 Basic bearing as tabulated is for zero movement in both the principal and transverse directions and is specified typically as S3E 150/0000. For additional movement C and E increase by 100mm per increment of principal movement and/or B and D increase by 100mm per increment of transverse movement when bearing is described in a code. e.g. BEARING TRANSVERSE MOVEMENT (cm)
PRINCIPAL MOVEMENT (cm) Bearing type column indicates maximum vertical design load in tonnes for ‘Working stress’ design or BS.5400 Serviceability Limit State. Larger bearings are available – details on request. ±3º (0.052 radians) rotation in any plane. 6
Fixings All bearings have provision for Grade 8.8 fixing bolts which are designed to cater f or the horizontal force t o which each specific type may be subjected, with some assistance from friction due to the minimum vertical load normally present in service. For ease of installation and to provide complete removeabilit y we suggest that the bearings be secured to cast-in sockets where possible. Freyssinet standard bolts and sockets may be provided as extra items, bolts are zinc plated.
Standard Fixing Socket
for removable bearings S3E, S3F and S3T
Available as an extra from Freyssinet Lt d. Sockets are provided uncoated.
Base or Top Plate
Bolt M12 M16 M20 M24 M30 M36 M42 M48 M56 M64
Ø'A' 25 40 40 40 50 70 90 100 100 120
'B' 60 70 100 160 220 220 220 250 350 400
3mm Natural Rubber Bolt I.S.O. metric (Grade 8.8, 10.9 or 12.9) Zinc plated.
Mild Steel Socket
Fixings All bearings have provision for Grade 8.8 fixing bolts which are designed to cater f or the horizontal force t o which each specific type may be subjected, with some assistance from friction due to the minimum vertical load normally present in service. For ease of installation and to provide complete removeabilit y we suggest that the bearings be secured to cast-in sockets where possible. Freyssinet standard bolts and sockets may be provided as extra items, bolts are zinc plated.
Standard Fixing Socket
for removable bearings S3E, S3F and S3T
Available as an extra from Freyssinet Lt d. Sockets are provided uncoated.
Base or Top Plate
Bolt M12 M16 M20 M24 M30 M36 M42 M48 M56 M64
Ø'A' 25 40 40 40 50 70 90 100 100 120
'B' 60 70 100 160 220 220 220 250 350 400
3mm Natural Rubber Bolt I.S.O. metric (Grade 8.8, 10.9 or 12.9) Zinc plated.
Mild Steel Socket
7
General arrangement drawings We suggest that before detailing general arrangement drawings are obtained with the latest information on dimensions and material specifications as the information in this publication is subject to change and updating.
Production & Overseas
Head Office
Units D1 – D3 Stafford Park 15 Telford Shropshire TF3 3BB Tel: +44 (0) 1952 201901 Fax:+44 (0) 1952 211919
6 Hollinswood Court Stafford Park 1 Telford Shropshire TF3 3DE Tel: +44 (0) 1952 201901 Fax:+44 (0) 1952 201753
Issue: 05 5/10/05
