TENSACCIAI Stay Cables
TENSACCIAI Stay Cables
TENSACCIAI Stay Cables
COMPANY PROFILE
Tensacciai, now 1951: Beginning of activity 2012: Tensacciai merges with Our mission is to constantly
1964: In the sixties Tensacciai Tesit, another successful con- improve the methods and the
renamed TENSA, undergoes a phase of remark- crete specialist contractor quality of construction process-
was founded in 1951 able growth in Italy. Post-ten- with international experience es through research, innovation
sioning is just at the beginning in post-tensioning, steel bars, and cooperation with design-
with headquarters of its history and its application structural bearings and expan- ers, engineers and contractors
in Milan, Italy. is still experimental. sion joints becoming a promi- worldwide. A strong commit-
1970: A programme of techno- nent player in the field of spe- ment to quality is the only way
It is now active in over logical renewal begins with the cialised subcontracting. to ensure safe and long-last-
50 countries with adoption of the steel strand. Tensacciai enters into a World- ing structures. We support the
1980: Tensacciai develops new wide Exclusive License Agree- design from the initial stage,
a direct presence in tensioning systems and equip- ment with Rome-based TIS challenging standards to devel-
14 countries. TENSA is ment in the field of ground an- (Tecniche Idraulico-Stradali S.r.l.) op custom solutions. We value
chors, combining innovation - a leading company with ex- timely execution and service as
a leader in stay cables, with versatility and ease of use. perience in designing and pro- keys to building long-term rela-
post-tensioning, 1990: New subsidiaries estab- ducing structural bearings, ex- tionships.
lished in Brazil, India and Aus- pansion joints and anti-seismic
anti-seismic devices, tralia and in Europe sister com- devices since 1973. Our core knowledge lies within
structural bearings panies in Portugal, Greece and 2014: TIS is acquired by Tensac- stay-cables and post-tensioning
the Netherlands. ciai. systems, anti-seismic devices,
and expansion joints. 2000: The internationalization 2015: TENSA is formed from the structural bearings and expan-
TENSA has process of Tensacciai continues merging and development of sion joints as well as all the
unabated. the three important companies related accessories, equipment
extensive references 2010: The company becomes mentioned above: Tensacciai, and services.
and numerous directly involved in projects in Tesit, TIS. TENSA strives to push its vast
all five continents. experience towards new meth-
certifications for its 2011: Tensacciai is acquired by ods and variations of appli-
products worldwide. Deal - world leading solutions cations, developing ingenious
provider in the field of bridge solutions for building new
construction - and becomes part structures, whether they are
of De Eccher Group. Tensacciai buildings or infrastructures, as
is now member of an organisa- well as the rehabilitation of ex-
tion capable of designing, manu- isting ones.
facturing and installing systems
everywhere in the world, thanks
to specialised technicians, en-
gineers in the technical depart-
ment and quality control. All
production and delivery process-
es are attested by the ISO9001
certification.
04
PRODUCT
CATALOGUES
01 - STAY CABLES
02 - POST TENSIONING
03 - GROUND ANCHORS
04 - EXPANSION JOINTS
05 - BEARINGS
06 - DAMPERS & STUs
07 - SEISMIC ISOLATORS
08 - ELASTO PLASTIC DEVICES
09 - VIBRATIONS CONTROL
Erasmus bridge, Rotterdam (The Netherlands)
02
STAY CABLE
SYSTEMS
TENSA started to develop its technology for cable stayed As a specialized contractor with decades of experience in the
bridges in the eighties. field, TENSAs Engineering Department is able to provide all
services related to the design, manufacture, and installation
The first small cable stayed bridge was built in 1988, pav- as well as monitoring of stay cables.
ing the way for the development of the resin-coated wedge
anchorage system that found its mature application in the Starting from the analysis of the whole structure, the design
bridge over the Garigliano river in Formia. of stays is executed, with shop drawings and specifications
for manufacturing, issuing of installation procedures with
Further on, the technical solution with waxed, polyethylene load and elongation checks along with further engineering
coated strands was adopted, finding its most famous appli- services.
cation in the renowned Erasmus bridge in Rotterdam, with New and customized solutions are continuously released, in
huge stays of 127 strands reaching more than 300 meters order to accommodate different projects.
in length.
TENSA directly follows all installation operations, with its
Through the years, continuous improvements have allowed own specialized teams and equipment being fully accounta-
TENSA to stay at the forefront of this technology, resulting in ble and operating under ISO 9001 quality assurance system.
the construction of more than 50 cable stayed bridges, using
its TSR stay cable system. The TENSA stay cable system can be used for several differ-
ent construction applications such as:
One of the most prestigious is the cable stayed bridge over
the river Po, designed for the high speed railway line from
Milan to Bologna, in Italy. It is the first known example of this
kind of structure.
Later on, TENSA completed the erection of a cable stayed Cable stayed bridges Suspended structures
bridge over the river Adige in Italy with 169 strands stays, Stays are used to connect Roofs, walkway coverages and
giving a maximum breaking load of more than 47.000 kN. pylons to deck, allowing a lightweight domes can be easily
considerable increase of span suspended with stay cables.
Several kinds of cable stayed bridges were built in different length.
places, with the TSR system being adopted also in the USA, Buildings and Structures for
India, Middle East along with the usual market place of Eu- Arch bridges technological services
rope. Stays act as vertical or inclined TLC Towers, wind power
hangers connecting arch to stations, exhibition columns
At this moment TENSA is directly involved in cable stayed deck. can be erected and stabilized
bridges projects in all five continents. with stay cables.
08
Erasmus bridge, Rotterdam
(The Netherlands)
PARALLEL STRANDS
STAY CABLE SYSTEM
The TENSA stay cable system has been designed Key advantages can be summarized as:
and tested in order to guarantee the highest levels
Higher protection against corrosion both in the anchorage
of performance, meeting the most stringent area and in the free length of stays
market requirements. Corrosion protection has been handled by adding different
layers of protection surrounding the main tension element
(i.e. steel strand). Anchorages and transition zones are pro-
vided with high performance anti-corrosion protection; seals
and water tight connections along the stays length guaran-
tee complete protection and enhanced durability.
Improved aesthetics
The use of compact size coloured ducts, special pin shape
anchorages and a variety of technical solutions for different
applications allow Owners and Designers to create stylish
solutions appealing to all users.
10
TSR STAY CABLE SYSTEM
This system features all the main advantages of the TSR sys-
tem and it is provided with a fork and pin connection that
links to a clevis plate on the structure.
It is available with fixed and adjustable anchorages.
It is suitable for all cable stayed bridges where there is a lack
of space in the pylon and deck connection area.
It is also frequently used in suspended structures where ca-
bles are used as suspension systems.
In these solutions the TSRF system is also provided with a
series of special clamps to fix vertical hangers to suspen-
sion cables.
The system design and the manufacturing of all the components meet the severe requirements of the most
important International standards such as FIB bulletin 30 Acceptance of stay cable systems using prestressing
steels, PTI Recommendations for stay cable design, testing, and installation and SETRA (CIP) Cable stays
Recommendations of French Interministerial commission on Prestressing.
11
TSR STAY CABLE
SYSTEM
06
05
03
07
01
04
02
12
08
10
09
PART NAME
01 PROTECTION CAP
03 ANTICORROSIVE COMPOUND
04 BEARING PLATE
06 FORM PIPE
09 ANTIVANDALISM/TELESCOPIC TUBE
13
SADDLE
SYSTEM
Through the years TENSA has been developing its technolo- A different kind of saddle, the TSS-B type, composed of a
gy for saddles, for both cable stayed and extra-dosed bridg- rectangular steel box filled with a high-strength compound,
es, as a response to issues affecting existing saddle designs can be used if the projects technical specifications allow it.
concerning fatigue, fretting corrosion and replacement of The entire bundle of strands is bonded to the pylon with high
cables. friction between the cable and the saddle.
One of the greatest advantages of the TSS saddle systems Full cables can be replaced, while strands can be tensioned
is to allow designers to simplify the pylon structure and use independently during installation phases.
very slender profiles to achieve an attractive appearance.
A third type, the TSS-ST steel box saddle system, is designed
The flagship system is the TSS-T multi-tube saddle, where as a curved steel structure embedded into the pylon, able to
single protected strands run individually within single re- accommodate standard TENSA TSR stay cable anchorages
cesses with adequate corrosion protection and provide guar- at both ends.
anteed differential forces resistance. Differential forces between the two stays connecting to the
Each strand is deviated individually in a specific hole, giving same saddle TSS-ST are absorbed by the steel saddle itself,
the following advantages: anchored tightly to the pylon; anchorages are kept outside
of the pylon.
Durability of corrosion protection, They remain accessible and inspectionable for any mainte-
Individual replacement of strands, nance from the outside of the pylon.
Resistance to fatigue identical to a standard stay ca- For this reason there is no need to have the inside of the py-
ble anchorage. lon shaped to accommodate ladders or spaces for accessi-
bility.
The steel saddle is then designed and manufactured accord-
ing to steel construction standards, i.e. Eurocode, and does
not need to be assessed through complicated and often un-
feasible laboratory tests.
Saddle System Type TSS-T
14
Cable stayed bridge, Montodine dAdda (Italy)
STAY
COMPONENTS
ANCHORAGES
STEEL STRANDS
16
STAY PIPES
17
SOLUTIONS
FOR VIBRATIONS
CONTROL
The mitigation of stay vibration is very important to avoid sipate the vibration energy. It is placed at the end of the tran-
dangerous occurrences of instability, increase of move- sition zone, close to the end of the form tube, allowing easy
ments and fatigue-related issues. Several solutions can be access for maintenance activities. It is mainly used in medi-
adopted to prevent and control unexpected events related to um-short stays.
stay vibrations.
Internal damper type TFVDi
(Tens Fluid Viscous Damper - internal)
DUCTS EXTERNAL SURFACE Dampers, to be used in medium-long stays.
They achieve the scope of damping different vibration am-
The external shape of the outer ducts can affect the stays plitudes in a wide range of frequencies, preventing the rise
behaviour under the effect of rain and wind. of visible oscillations (unpleasant to observe) and the sub-
It has been proven under testing that a special shaped dou- sequent emergence of dangerous fatigue-induced damage.
ble helicoidal rib placed on the external surface of the ducts They remain within inner section of the stay, at the end of the
can significantly improve the efficiency in suppressing the transition zone and can be easily inspected and maintained.
risk of vibration amplification, minimizing the drag forces at
the same time. External damper type TFVDe
(Tens Fluid Viscous Damper - external)
When long stays require a considerable amount of energy to
COMPACTED BUNDLE be dissipated, it is preferable to use external dampers.
The dampers connect the stays to rigid steel structures
The use of compacted bundles of strands (slim stays) placed on the deck. This way longer damping strokes are
helps minimize the drag forces induced to the stays by the available as well as increased damping capacity.
blowing wind. Such a countermeasure should be adopted The dampers can be made of one or two single devices.
with special care in the case of long span bridges, where This kind of solution is capable of achieving the highest
transversal forces induced by wind may also affect the stays damping requirements, far above the minimum logarith-
connections to pylons and decks. mic damping ratios needed on site (6% and more). Suitable
calculation models are available to determine the damper
properties (damping factor, load, stroke, other) for each sin-
DAMPERS gle stay in a specific project and its relevant site conditions.
Parallel strand stay cables are provided with a very low in-
trinsic logarithmic damping ratio, in the 0.5% - 2.5% range. CROSS TIES
Different kinds of dampers are available to achieve the
damping performance required by each project. In some special cases where instability is a problem, it may
There can be internal or external dampers. The choice for be necessary to install cross-ties, placed in the vertical
the best solution depends on the level of performance re- plane of stays. They act in order to increase the natural fre-
quired and the local conditions of the project (geometry, quencies of cables and the wind speed threshold that trig-
length of the stays, wind field). gers instability phenomena.
In any case it is important to highlight the difficulties with
Internal damper type TRD (Tens Rubber Damper) installation and maintenance. Proper function and efficiency
It is the simplest device that can be used to mitigate stay vi- are only guaranteed in the vertical plane.
brations and utilises a high damping elastomeric ring to dis-
18
Cable stayed bridge over the Adda river, Calolziocorte (Italy)
ADDITIONAL
OPTIONS
All TENSA stay cable systems can be provided (if required) Loads can be monitored with the use of permanent load
with supplementary options such as: cells placed over anchorages.
The load cells can be mono-strand, where the load cell is
Structural Monitoring placed over only one strand of the anchorage, giving the stay
Monitoring of stay cables is important during construction the full load, extrapolated as the single strand load. Or they
and service life of the bridge and it becomes critical in many can be annular, resting directly beneath the nut of the ad-
cases. justable anchorage and providing readings of the load acting
Several parameters can be monitored, in order to collect over the entire stay.
data that help in: All load cells are designed to minimize sensitivity to unusu-
- Validation of design and construction assumptions, to im- al loads and bearing surfaces and can be connected to an
prove construction techniques; data acquisition system, providing summary of readings tak-
- Detection of possible damage and unexpected behav- en from different cells.
iour; This way full monitoring of all stays can be performed, giving
- Developing efficient maintenance processes a real-time status of the bridge during its lifetime.
- Reducing the costs in the life cycles of structures. Vibration monitoring systems can be provided, both with ac-
celerometers placed directly over stays or through an inno-
vative radar detection system, that allows detection of loads,
vibration amplitudes and proper frequencies through inter-
ferometric radar devices.
This latter system guarantees proper readings and reduced
project site activities, while providing accurate and reliable
results.
Fire protection
Stays can be equipped with different fire protection systems
in the lower portions, especially for bridges where there is
an increased risk of exposure to fire due to heavy vehicular
traffic.
Lighting systems
Special lighting systems can be installed, providing aesthet-
ically pleasing illumination of the stays, complying with ar-
chitectural requirements, which of course do not affect the
function and the installation of the stays.
20
Cable stayed bridge
over the river Belbo,
Nizza Monferrato (Italy)
Cable stayed bridges on the Favazzina viaduct, Scilla (Italy)
03
PRODUCT DEVELOPMENT
AND TESTING
24
TESTING
25
Arch bridge over
the Twente channel,
Eefde (The Netherlands)
04
SYSTEM PROPERTIES
AND DIMENSIONS
When the strands are used according to ASTM A416, the values specified above must be reduced accordingly
(1) Based on steel strand specification as per prEN 10138-3
(2) Recommended maximum service stress for stay cable as per FIB bulletin 30 and Setra
(3) Recommended maximum service stress for extra-dosed bridges as per Setra
28
Cable stayed bridge over the Bacchiglione river, Montegalda (Italy)
0A1
TSR
B1(1)
SYSTEM
G1(2) H(2)
0I1
F (1) 0C1 0D1 G1(2)
0A1
0E (2)
B1(1)
G1(2) H(2)
Main dimensions (using steel strand diameter 15.7 mm and grade 1 860 MPa)
N of E H
STRANDS A1 B1(1) C1 D1 STANDARD SLIM F(1) G1(2) STANDARD SLIM I1
0I1
[mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm]
12 190 375 160 193.7 110 110 40 300 910 1 250 255
19 225 390 180 219.1 125 110 50 320 1 010 1 420 290
27 260 410 217 254 160 140 60 390 1 330 1 860 330
31 275 415 230 267 160 140 70 400 1 330 1 860 345
37 280 430 237 273 180 160 80 410 1 460 2 070 355
43 320 475 267 305 200 180 80 425 1 660 2 360 400
55 335 475 282 323.9 200 180 90 445 1 770 2 490 425
61 360 550 305 355.6 225 200 100 475 1 920 2 730 445
73 390 590 325 368 250 225 100 525 2 080 2 950 475
91 425 650 365 419 280 250 120 555 2 330 3 340 525
109 450 700 380 431.8 280 250 125 585 2 500 3 560 550
127 500 750 425 482.6 315 280 130 615 2 800 4 010 600
169 570 900 485 558.8 400 315 145 655 3 220 4 620 680
30
0A2
B2 (1)
H (2) G2 (2)
0A2
(2)
B2 (1)
0E
H (2) G2 (2)
N of E(2) H
STRANDS A2 B2 (1)
C2 D2 STANDARD SLIM F(1) G2(2) STANDARD SLIM I2
[mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm]
0I2
4 160 300 140 168.3 63 63 20 325 430 580 190
12 220 440 200 229 110 110 40 345 860 1 200 250
19 280 450 235 267 125 110 50 360 960 1 370 310
27 320 480 270 305 160 140 60 380 1 280 1 810 350
31 330 500 285 323.9 160 140 70 390 1 280 1 810 360
37 345 500 290 323.9 180 160 80 400 1 410 2 020 375
43 390 560 330 368 200 180 80 435 1 610 2 310 420
55 410 560 345 394 200 180 90 450 1 720 2 440 445
61 440 610 370 419 225 200 100 450 1 870 2 680 475
73 475 650 400 445 250 225 100 470 2 030 2 900 510
91 520 700 435 482.6 280 250 120 505 2 280 3 290 555
109 545 740 460 508 280 250 125 540 2 400 3 460 580
127 600 800 510 558.8 315 280 130 580 2 700 3 910 640
169 680 900 580 635 400 315 145 670 3 120 4 520 720
31
Viaduct over wharf VII, Trieste (Italy)
TSRF
SYSTEM
FIXED FORK
CONNECTION
A
B C
H
G
F
D
E
N of
STRANDS A B C D E F G H
[mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm]
33
ADJUSTABLE FORK CONNECTION
N of
STRANDS L M N P Q F G H
[mm] [mm] [mm] [mm] [mm] [mm] [mm] [mm]
34
Viaduct over wharf VII, Trieste (Italy)
Cable stayed bridge over the Sangone river, Giaveno (Italy)
05
INSTALLATION
Installation plays an extremely critical role Installation of the TSR / TSRF systems is always carried out
in the proper performance of the systems. on site by experienced TENSA teams, all over the world. Our
teams take care of all phases, on the back of many decades
Decades of experience and trained of experience in the field and thanks to dedicated working
specialized teams are the key for good procedures.
Installation is carried out with a strand by strand sequence,
performance. guaranteed by means of lightweight specially designed in-
stallation equipment.
Preliminary operations consist of the welding of the external
pipes to the final length and the cutting of strands over spe-
cial benches, starting from coils, to reach the correct meas-
urements.
With the anchorages already placed at pylon and deck lev-
el, the pipe is lifted with a tower crane and the first strand is
threaded, following a pre-defined sequence.
Stressing is carried out while placing strands, one by one,
with the use of a special TENSA mono-strand jack, provided
with a system of load and elongation measuring.
This step is carried out using the iso-elongation principle:
stressing is done comparing the same position of marks
placed over strands, guaranteeing the same load acting over
each strand of the bundle.
Once the entire stay is installed, further stressing with the
mono-strand jack may be carried out.
Final small regulations of loads are performed with the use
of a TENSA adjusting jack, acting directly over the adjustable
anchorage and turning the nut to its final position.
Once the stressing operations are completed, final injections
and closures are carried out.
Installation can be also carried out with pre-fabricated stays
depending on site conditions and construction needs.
Stays load adjustment, single strand and full stay cables
substitution can be carried out anytime with reduced impact
on the structures performance.
Cable stayed bridge over the Kwanza river, Barra do Kwanza (Angola)
38
TYPE OF A (MIN) B (MAX STOKE)
JACK [mm] [mm]
N of
STRANDS D C max
[mm] [mm]
4 - 7 - 12 425x425 950
19 - 31 - 37 - 42 - 55 585x585 1165
61 650x650 1165
73 705x705 1295
91 750x750 1320
39
Cable stayed bridge over the Adige river, Piacenza dAdige (Italy)
Job title Job No.
Item
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