DYWIDAG Multistrand Stay Cable Systems - DSI Civil

 
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DYWIDAG Multistrand Stay Cable Systems - DSI Civil
DYWIDAG Multistrand Stay Cable Systems
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
2
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
Contents

History�������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 4
DYNA Grip® Stay Cable System����������������������������������������������������������������������������������������������������������������������������������������������������������� 6
  High Fatigue Performance��������������������������������������������������������������������������������������������������������������������������������������������������������������� 6
  Durability and high-quality Corrosion Protection����������������������������������������������������������������������������������������������������������������������������� 7
  Replaceability of Strands����������������������������������������������������������������������������������������������������������������������������������������������������������������� 7
  Fast Construction Cycles����������������������������������������������������������������������������������������������������������������������������������������������������������������� 7
  Drawing�������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 8
DYNA Grip® Stay Cable System – Optional Solutions������������������������������������������������������������������������������������������������������������������������ 10
  Vandalism Protection & Guide Deviator����������������������������������������������������������������������������������������������������������������������������������������� 10
  Cable Hardening���������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 11
  Fire Protection�������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 12
  Cable De-icing������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 13
  Clevis Anchorage��������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 14
DYNA® Link Anchor Box System�������������������������������������������������������������������������������������������������������������������������������������������������������� 16
  Advantages to Conventional Pylon Solutions�������������������������������������������������������������������������������������������������������������������������������� 16
  Advantages in Comparison to Conventional Saddle Solutions����������������������������������������������������������������������������������������������������� 17
  Stay Cable Installation������������������������������������������������������������������������������������������������������������������������������������������������������������������� 19
Saddle Solution���������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 20
  Saddle with Individual Tubes��������������������������������������������������������������������������������������������������������������������������������������������������������� 20
Fully Grouted Solutions���������������������������������������������������������������������������������������������������������������������������������������������������������������������� 22
   DYNA Bond® Anchorage���������������������������������������������������������������������������������������������������������������������������������������������������������������� 22
   Saddle with Anchor Groove and Pin���������������������������������������������������������������������������������������������������������������������������������������������� 23
Strand and Wedge������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ 24
   Epoxy Coated Strands������������������������������������������������������������������������������������������������������������������������������������������������������������������� 24
   Outer Stay Pipe������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ 25
Cable Damping����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 26
  Excitation Causes�������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 27
  Damper Design������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ 28
Full Size Testing���������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 30
   Standard Fatigue and Tensile Testing�������������������������������������������������������������������������������������������������������������������������������������������� 30
   Fatigue and Tensile Testing with higher load level and additional Transverse Deflection��������������������������������������������������������������� 30
   Fatigue and Tensile Testing with additional Transverse Deflection (Setra)������������������������������������������������������������������������������������� 31
   Increased Load Cycle Testing – 10 Million Cycles������������������������������������������������������������������������������������������������������������������������� 31
   Monostrand Fatigue Testing under Reversed Cyclic Flexural Loading������������������������������������������������������������������������������������������ 32
   Leak Tightness Test����������������������������������������������������������������������������������������������������������������������������������������������������������������������� 33
Cable Installation�������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 34
Stressing��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 36
   ConTen Stressing��������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 36
DYNA Force® Elasto-Magnetic Sensor����������������������������������������������������������������������������������������������������������������������������������������������� 38
  Functional Principle����������������������������������������������������������������������������������������������������������������������������������������������������������������������� 38
  System Components��������������������������������������������������������������������������������������������������������������������������������������������������������������������� 38
  System Advantages in Comparison to other Measuring Systems������������������������������������������������������������������������������������������������� 38
  Quality Assurance�������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 39
  Practical Applications�������������������������������������������������������������������������������������������������������������������������������������������������������������������� 39
Cable Inspection�������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 40
  Visual Inspection���������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 40
  Vibration Measurement������������������������������������������������������������������������������������������������������������������������������������������������������������������ 41
  Magnetic Flux Leakage Inspection������������������������������������������������������������������������������������������������������������������������������������������������ 41
References����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 42
  Stay Cable References������������������������������������������������������������������������������������������������������������������������������������������������������������������ 42
  Extradosed Bridges����������������������������������������������������������������������������������������������������������������������������������������������������������������������� 46
  Arch Bridges���������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 48
  Special Applications���������������������������������������������������������������������������������������������������������������������������������������������������������������������� 49

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DYWIDAG Multistrand Stay Cable Systems - DSI Civil
History

DYWIDAG-Systems International (DSI) is a globally leading system supplier of innovative technologies for the construction industry.

Tradition                                      Research & Development                       Certifications and
                                                                                            International Organizations
The long tradition of DSI reaches back         Continued investments in Research &
as far as 1865 – the founding year of the      Development and the resulting patent         International organizations, trade
German construction firm, Dyckerhoff           applications sustainably strengthen          associations and standards committees
& Widmann AG (DYWIDAG). DSI was                the know-how available within the            are becoming more important in times
founded in the year 1979 to market             DSI Construction Group. By offering          in which products and services seem
DYWIDAG Systems and technical know-            innovative solutions in accordance with      more and more interchangeable.
how around the world and to develop            superior quality standards, we fulfill the   Organizations and trade associations
innovative systems resulting from its          constantly changing requirements of our      are cross-linked on a global basis and
own R&D activities.                            target markets. It is our declared aim to    promote the exchange of technology
                                               always be one step ahead.                    and know-how across borders. We are
DSI Technology                                                                              an active member in many International
                                               Client Orientation                           Organizations to drive technical
In more than 50 countries and at 15                                                         developments. In April 2016, DSI
regional manufacturing sites, DSI              The needs and requirements of clients        received a general technical approval for
Construction develops, produces                and business partners are always of          DYNA Grip® Multistrand Stay Cables for
and supplies high quality systems              paramount importance. Our company            Stay Cable Bridges. It is the world’s first
such as DYWIDAG Post-Tensioning                is characterized by reliability, trust and   approval to regulate Multistrand Stay
Systems, Geotechnical Systems and              cooperation based on partnership.            Cable Systems.
“Concrete Accessories”. In accordance          We offer our clients the advantages of
with our slogan “Local Presence                an international system supplier with
– Global Competence”, more than                a product range that is tailored to suit
1,400 specialized and experienced              individual requirements.
DSI employees ensure that DSI’s
                                                                                                                                                                (German Institute for Civil Engineering)

technologies and know-how are                                                                                                                                    Approval Office for Construction Products and
                                                                                                                                                                 Construction Methods

                                                                ears of Servi
                                                                                                                                                                 Testing Office for Structural Engineering

available around the world. DSI offers
                                                                                                                                                                 A statutory body commonly sponsored by the

                                                             0 Y
                                                                                                                                                                 German national government and the German

                                                           5                  ce                 General Construction                                            Lander
                                                                                                                                                                 Member of the EOTA, UEAtc and WFTAO

quality on all levels – quality that is                  1                                       Supervisory Authority
                                                                                                 Approval
                                                                                                                                                                Date:                               Reference No.:
                                                                                                                                                                April 19, 2016                      I 30-1.14.7-105/15

characterized by creativity, reliability and
profitability.                                                                                   Approval No.:
                                                                                                 Z-14.7-759
                                                                                                                                                                 Period of validity
                                                                                                                                                                 from: April 19, 2016
                                                                                                                                                                 to: April 19, 2021

                                                                                                 Applicant:

Comprehensive Services
                                                                                                 DYWIDAG-Systems
                                                                                                 International GmbH
                                                                                                 Destouchesstrasse 68
                                                                                                 80796 München

                                                                                                 Subject of approval:

Our comprehensive services include
                                                                                                                                                    ®
                                                                                                 DYWIDAG - Multistrand Stay Cable DYNA Grip

the conception, design, planning and                                                             The above-mentioned subject of approval is hereby granted a general construction supervisory
                                                                                                 authority approval.
                                                                                                 This general construction supervisory authority approval comprises 15 pages and 23 appended

installation of its systems as well                                                              sheets.

as quality management and on site                                                                                 Important Notice
                                                                                                                  This general construction supervisory authority approval is the

supervision.                                                                                                      translation of a document originally prepared in the German language
                                                                                                                  which has not been verified and officially authorized by the “Deutsches
                                                                                                                  Institut für Bautechnik“ (German Institute for Civil Engineering). In case
                                                                                                                  of doubt in respect to the wording and interpretation of this approval,
                                                                                                                  the original German version of this document shall prevail exclusively.
                                                                                                                  Therefore, no liability is assumed for translation errors or inaccuracies.

                                                                                                 DIBt I Kolonnenstrasse 30 B I D – 10829 Berlin I Phone:+49 30 78730–0 I Fax:+49 30 78730–320 I E-mail: dibt@dibt.de I
                                                                                                 www.dibt.de

1994: Odawara Blueway Bridge, Odawara, Japan

  4
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
History

Milestones
DYWIDAG Post-Tensioning Systems and            which is known as the first extradosed
Stay Cable Systems are world renowned          bridge in the world – as well as for Kap
for reliability and performance; they are      Shui Mun Bridge (Hongkong) in 1995
perfectly suitable for all applications        are two outstanding milestones in DSI’s
in post-tensioned construction. They           stay cable history.
embrace the whole spectrum from
bridge construction and buildings to civil     Established in 2000 and still used
applications – both above and below            today, the DYNA Grip® System already
ground.                                        took into account the requirements for
                                               modern cable systems at the turn of the
In addition to traditional post-tensioning     millennium.
systems with bars, DSI offers a
complete product line in strand post-          Our stay cable systems have always
tensioning (bonded, unbonded and               combined the highest safety and
external) as well as stay-cable systems        reliability standards with excellent
to fulfill the changing requirements in        economical efficiency in their research
the industry today and tomorrow.               and development.

As a further developement of the               Dependable corrosion protection
first cable stayed bridges in the 60’s         methods, damper design, fire protection,
and 70’s of the last century, new              vibration measurements and the recently
systems were introduced into the               developed DYNA Force® monitoring
market considering new materials and           system significantly con­tribute to the
increasing requirements on modern              longevity of modern construction and
infrastructures. The application of DSI’s      cable hardening for mitigating multiple
stay cable system for the Odawara              threat scenarions (vandalism, fire, blasts
Blueway Bridge (Japan) in 1994 –               etc.).

2000: Victoria Bridge, Rosario, Argentina                                                   1972: 2. Main Bridge, Hoechst Chemicals,
First DYNA Grip® Stay Cable Bridge                                                          Frankfurt, Germany

1995: Kap Shui Mun Bridge, Hongkong, China
DYNA Bond® Stay Cable Bridge with 176 cables

                                                                                                                                   5
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
DYNA Grip® Stay Cable System

                                             Leak Tightness
                                             Gap between threads is filled with
                                             corrosion protection compound for
                                             improved tightness

                        Replaceability
                        Exchange of single strands including
                        PE-coating through anchorage → no
                        interruption of traffic

                                                                                                    Excellent Durability
                                                                                                    A watertight and adjustable sealing unit
                                                                                                    and strands with PE-sheathing up to the
                                                                                                    wedge meet highest demands. No devia-
                                                                                                    tion of strands in the wedge gripping zone

                                                                      High Fatigue Capacity
                                                                      Compliance with internatio-
                                                                      nal fib and PTI standards

The DYNA Grip® Stressing Anchorage          High Fatigue Performance
consists of an anchor block in which the
strands are anchored by high fatigue 3      The system has proven its excellent             ■■ Tests on single strands under reversed
part-wedges. A ring nut is threaded onto    performance and fulfills the                       cyclic flexural loading with 45% and
the anchor block to transmit the cable      requirements of fib Bulletin 30 as well as         60% GUTS, 2 million load cycles
force into the structure via the bearing    PTI & Setra requirements for fatigue and           with anchorages inclined by 3.0° and
plate. A steel pipe which incorporates      tensile strength:                                  additional angular deviation between
bending and sealing provisions for the      ■■ Multiple full size tests on cable sizes         ± 10mrad and ± 35mrad
strands is part of the anchor block.           from 7 to 156 strands
A non-adjustable anchorage with the                                                         The leak tightness of the anchorage
                                            ■■ The system has been successfully
same provisions for bending and sealing                                                     area has been demonstrated for the
of the strands can be placed at the            tested in standard tests with a stress
                                                                                            complete system and even meets
dead-end side.                                 range of up to 200MPa at an upper
                                                                                            stringent fib and Setra requirements
                                               stress limit of 45% GUTS and at
                                                                                            with:
                                               2 million load cycles with anchorages
                                               inclined by 0.6°. In addition, full          ■■ Up to 3m water head
                                               size tests have been performed               ■■ Several load cycles in the longitudinal
                                               successfully with an upper load of up           and transverse direction
                                               to 60% GUTS, up to 10 million load           ■■ Temperature cycling 20–70°C
                                               cycles and a stress range of up to
                                               250MPa

  6
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
DYNA Grip® Stay Cable System

                                                                                                                      Free Length
                                                                                                                      Strands additionally
                                                                                                                      protected by UV-re-
                                                                                                                      sistant stay pipe.
                                                                               Protection against Impact              Outer helical fillet for
                                                                               Usually used for vanda-                reducing wind-rain
                                                                               lism protection. Can also              induced vibrations
                                                                               be upgraded to a cable
                                                                               hardening system resisting
                                                                               fire and other multiple
                                                                               threat scenarios
                                                                               (blasts, cutting etc.)
                                                    Compaction Clamp
                                                    With straight guidance and smooth
                                                    inner radius for optimized cable
                                                    bending and minimized transverse
                                                    pressure. Also serves as supporting
                                                    structure in case a guide deviator or
                                                    damper is installed

Durability and high-quality Corrosion Protection
Strands are guided into the anchorage           The anchorages have been designed               Free length:
by an elaborate system that ensures             for threading the strands including their       ■■ The strands are protected by a multi-
both leak tightness and smooth                  PE-sheathing through the anchorage:                layer system of galvanized wires and
­deviation:                                     ■■ Dismantling of the strand’s PE-                 are tightly sheathed by HDPE. A wax
 ■■ Compressible sealing plates ensure             sheathing is minimized to what is               filling is used for the interstices in
    water and even vacuum tightness                absolutely necessary.                           between.
 ■■ The correct function can be checked         ■■ The factory applied corrosion                ■■ An outer stay pipe made of UV-
    and even adjusted during inspection            protection of the strands continues             resistant HDPE additionally protects
 ■■ Bending stresses are minimized by              directly up to the wedges.                      the strands and minimizes rain-wind
    a filter that arranges a straight-line      ■■ Significant reduction of the length             induced vibrations with an outer
    entering into the wedge gripping area          of anchorage area where interstices             helical fillet that provides a low drag
                                                   are filled with corrosion protection            coefficient.
 ■■ A cap including filler material for the
    protection of individual strands is            compound. Both high durability and
    placed in front                                cost savings in terms of additional
                                                   filling material are guaranteed.
 ■■ Corrosion protection resists ­corrosivity
    class C5 in accordance with
    ISO 12944

Replaceability of Strands                       Fast Construction Cycles
As the PE-coating is pulled directly            ■■ Lightweight equipment for strand             ■■ No exact dismantling of the strand’s
through the anchorage, an exchange of              installation and stressing operations is        outer sheathing is necessary. In
strands is possible at any time during             provided by DSI.                                case of stressing actions that are
the service life of the bridge without the      ■■ The use of tower cranes or other                additionally required, the strand
need for renewing or replacing any other           lifting equipment can be limited to a           sheathing is compressed by small
cable components.                                  minimum.                                        tubes in front of the wedges while the
■■ Strand exchange is performed directly                                                           strand is pulled through and elongated
                                                ■■ Non-protruding recess pipes at the
   at the anchorages                                                                               by the jack.
                                                   pylon → no additional formwork
■■ There is no need for moving the                 adjustment is required.                      ■■ A compaction clamp, installed after
   cable’s outer stay pipe for accessing                                                           stressing on the strand bundle, keeps
   the strand bundle either at the deck or                                                         the strand in a compact hexagonal
   outside the pylon – no dis­ruptions to                                                          pattern.
   traffic.

                                                                                                                                            7
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
DYNA Grip® Stay Cable System

Drawing

                                    Ring Nut

                  Compression Tubes                 Sealing Plates

                           Wedges                       Spacer                                 Strands
                                                                                                                                     Compaction Clamp

                                                           Compression Plate

                                                                                                                                                                ∅P
oA
         ∅R

                                                                   ∅T

                                                                                                                                                       HDPE Sheathing
                                          D    C
     Cap        Anchor Block                             Bearing Plate               Recess Pipe                         Vandalism Protection Pipe

                                          B
                                                                            min LS

DYNA Grip® Anchorage – Technical Data
(forces calculated with strands 0.62" St 1660/1860)

                                  Cable type *                                        DG-P4               DG-P7              DG-P12          DG-P19             DG-P31
                                  No. of strands                                          4                  7                  12               19                31

                         Forces [kN] **
                         Ultimate load at 100% GUTS                                    1,116               1,953              3,348            5,301             8,649
                   Service load at 50% GUTS for stay cables                             558                 977               1,674            2,651             4,325
               Service load at 60% GUTS for extradosed tendons                          670                1,172              2,009            3,181             5,189

                       Dimensions [mm]
                         Bearing plate ***                            ¨A                190                 250                300              370               460
                         Bearing plate ***                              C                20                  25                 30               35                40
                      Bearing plate opening                           ∅T                112                 145                183              219               267
                            Thread ****                                 B               160                 170                200              220               230
                               Ring nut                                 D                50                  50                 90              110               120
                               Ring nut                               ∅R                150                 210                244              287               350
                           Dead anchor                                  E                50                  90                120              120               135
                           Dead anchor                                ∅F                150                 190                215              261               324
          Distance of compaction clamp, stressing end                min LS             520                 650                880             1,080             1,350
              Distance of compaction clamp, dead end                 min LD             430                 540                770              970              1,240
                         HDPE sheathing                               ∅P                 63                  90                110              125               160
                       HDPE transition tube                           ∅S                110                 140                200              225               250
*	 larger sizes on special request
**	 local design guidelines must be taken into account
*** 	 dimensions correspond to concrete strength ≥ 35MPa (cylinder) at 45% GUTS according to PTI anchorage zone design
**** 	 standard length, changeable on special request
Subject to modification

     8
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
DYNA Grip® Stay Cable System

       HDPE Sleeve                                                              Dead Anchor
           ∅S

                                                                                                                oA
                                                                                                     ∅F
                                                                      ∅T
                                                                                     C        E

                                                        min LD

DG-P37          DG-P43       DG-P55   DG-P61   DG-P73      DG-P85     DG-P91          DG-P109     DG-P127
  37                  43       55       61       73              85        91             109       127

10,323           11,997      15,345   17,019   20,367       23,715    25,389             30,411    35,433
 5,162               5,999    7,673    8,510   10,184       11,858    12,695             15,206    17,717
 6,194               7,198    9,207   10,211   12,220       14,229    15,233             18,247    21,260

 500                 600      600      640      715          780       780                855       910
  45                  55       60       65       70              75        80             85        90
 293                 329      341      371      403          429       455                479       531
 240                 250      270      275      290          300       310                340       350
 130                 140      160      165      180          190       200                230       240
 378                 420      440      480      536          554       600                636       700
 135                 150      170      170      185          190       195                210       220
 354                 398      420      450      490          522       550                586       645
 1,500               1,690    1,750    1,920    2,070       2,170      2,340             3,020     3,390
 1,390               1,580    1,640    1,810    1,960       2,050      2,230             2,910     3,280
 180                 180      200      225      250          280       280                315       315
 250                 315      315      315      355          355       355                450       450

                                                                                                            9
DYWIDAG Multistrand Stay Cable Systems - DSI Civil
DYNA Grip® Stay Cable System – Optional Solutions

Vandalism Protection & Guide Deviator
The DYNA Grip® Stay Cable System can be easily adjusted or upgraded if required:
■■ The length of the vandalism protection ■■ On special request, guide deviators       ■■ DSI has patented (EP2729621 B1;
   pipe can be adjusted to project           can be provided both at the deck and         US9009899 B2) an eccentric flange
   specific requirements to achieve any      at the pylon to:                             connection between the recess pipe
   requested height above the bridge         ■■ reduce cable bending at the               and the housing for the guide deviator.
   deck level. It can be made of 2 long         anchorages                                The eccentric flange connection
   parts or customized for retrofitting      ■■ decrease cable vibrations                 ensures that eccentricities caused by
   purposes.                                                                              wrong installation angles of the recess
                                                                                          pipe can be compensated.

                                                                                    HDPE Sheathing

                                               Vandalism Protection Pipe

                              Guide Deviator

Eccentric Flange Connection

                                                                                              Deck Superstructure

 10
DYNA Grip® Stay Cable System – Optional Solutions

Cable Hardening
DSI’s cable hardening system has been developed to protect the stay cables effectively against multiple threat scenarios for all stay
cable sizes.

■■ Any kind of mitigation level in terms of     ■■ Numerical simulation and physical            ■■ Therefore, DSI’s Cable Hardening
   specific customized threat scenarios            testing is carried out using expertise          system is designed according but
   and the required strength of the                from Fraunhofer Institute for High              not limited to the typical and notable
   protection system can be taken into             Speed Dynamics (Ernst-Mach-                     threats as shown in table below
   consideration.                                  Institute)                                   ■■ Adaptable for bridge retrofitting
■■ Highly effective protection material         ■■ Validation of different scenarios with          applications using half-shell
   can be easily adjusted to requirements          specific threats following bridge               technology
   and threats                                     security guidelines (e.g. AASHTO)

Cable Hardening shows advantageous performance characteristics:
■■ Eases installation and is adjustable to ■■ Incorporates adjacent functional cable            ■■ Allows easy inspection and
   different bridge construction methods      units like dampers either internally or              maintenance of the protection system
■■ Can be adjusted to any kind of bridge      externally                                           itself but also the stay cable system in
  construction layout within anchorage                                                             general
  and transition zones

Cable Hardening Threat Resistance

           Threat                          Type                        Available
             Fire                    Hydrocarbon Fire                     Yes

                                           HEIED                          Yes
       Explosive Device
                                           VBIED                          Yes

                                      Thermal Cutting                     Yes

    Non Explosive Device            Mechanical Cutting                    Yes

                                     Exothermic Lance                     Yes

                                                                                                 Exothermic Lance

                                                                                            Outer Pipe

                                Highly effective Protection Material

                                        Inner Pipe

Strand Bundle

                                                                                                                                        11
DYNA Grip® Stay Cable System – Optional Solutions

Fire Protection
Lightning, a car accident or other
external incidents may cause fire on
a bridge. In that case, the main parts
of the stay cable system need to be
protected against damage.

HDPE Sheathing

                        Fire Protection Mat
Strand Bundle

Fire Protection Mats for the Free Cable Length

DSI’s stay cable system fully complies        ■■ Used for the free length of the stay
with PTI requirements for fire resistance        cable
and has been verified using the load          ■■ Covered by standard HDPE sheathing
capacity test at 300°C.
                                              ■■ Mats have a hydrophobic behavior to
                                                 avoid water absorption
Furthermore, special fire protection mats
resist a 1,100°C hydrocarbon fire for at      ■■ Any other fire resistance period can be
least 30 minutes without the strands             achieved easily by modifying the mat
heating up to above 300°C, thus fully            thickness
complying with PTI requirements.              ■■ Application in cable transition zone is
                                                 possible

                                                                                           PTI Load capacity test at 300°C

 12
DYNA Grip® Stay Cable System – Optional Solutions

Fire Protection
Anchorage Area

■■ Steel parts in the anchorage area can      ■■ Protection has been demonstrated              ■■ Fire protection coating fulfills the
   be coated with a special fire protection      during laboratory tests                          highest requirements according to
   coat that is intumescent under heat                                                            standard ISO 12944, corrosivity
   impact and thus protects                                                                       class C5
   the steel parts

Anchorage Protection System
                                                            Bearing Plate

                        Cap

Intumescent Coating

                                                                                           Ring Nut

                                                                            Anchor Block

Cable De-icing

Methods are available to reduce the risk      eliminating the risk of harming the cable        climatic conditions, DSI closely cooper-
of snow and ice accumulation falling          structure.                                       ates with globally recognized expertise
from stay cables and endangering traffic                                                       and testing facilities.
running on the bridge’s superstructure.       In order to comply with client specific
Patented measurements are designed,           needs in dependance of different

                                                                                                                                         13
DYNA Grip® Stay Cable System – Optional Solutions

Clevis Anchorage
■■ Architectural requirements for the            Fatigue tests were carried out at     The tests respected an inclination
   design of stay cable bridges are              the Technical University of Munich    of 0.6° – even towards the inflexible
   steadily increasing. Pylons often need        in accordance with fib Bulletin 30    centerline – and an upper load of 0.45
   to be as slim and elegant as possible.        requirements.                         GUTS. They were carried out with a
■■ Solutions are needed in which the stay                                              stress range of 200N/mm² at 2 million
   cables are connected to the structure                                               load cycles.
   outside of the pylon if the space inside
   the pylon is insufficient for common                                                These dynamic tests, as well as the
   stay cable anchorages that are                                                      subsequent static tensile tests, were
   supported by bearing plates.                                                        performed with outstanding success.
■■ DSI developed the DYNA Grip® Clevis
                                                                                       The clevis anchorage is not only suitable
   Anchorage for strand cable types
                                                                                       for stay cable bridges, but can also be
   DG-P4 to DG-P61 as standard sizes
                                                                                       used for arch bridge hangers where
   with additional types on request,
                                                                                       available space in the arch is too small
   offering an economic alternative to
                                                                                       for aligning ordinarily fixed anchors.
   conventional systems that have been
   used so far.
■■ The complete strand cable can                                                                       Gusset Plate
   be easily pre-assembled on the
   superstructure and is lifted into its final
   position afterwards.                                                                Anchor Block
■■ DSI offers special tools for the
   preassembly of the clevis as well as
   the mounting of the pin into the clevis
   hole.
■■ Restressing of individual strands
   as well as the replacement of the
   complete strand bundle is possible.
■■ This system also offers other
   DYNA Grip® System advantages.
                                                 Compaction Clamp                                              Pin and
                                                                                                               Pin Retainer
                                                                                                      Clevis

                                                                                      Flange Tube

        HDPE Transition Tube

HDPE Sheathing

 14
DYNA Grip® Stay Cable System – Optional Solutions

Clevis Anchorage

                                                                                                      Wedge Keeper Plate

                                                                                                                               Corrosion
                                                                                                       Anchor Block            Protection Compound

                                                                                                    Sealing Plates                           Pin Retainer

                                                                                                       Spacer                          Pin            Clevis

                                                                                                                      ØA
     HDPE Sheathing                   Compaction Clamp                                   Compression Plate
                                                                            ØS
ØP

                                                                                                                                                            F
                                                                     HDPE Transition Tube, Clevis                                      D          C

                                                                                                                                             ØE
                                                                                             Flange Tube        Wedges
                                                                                                                                             ØG

                                                                                  H                                                B

DYNA Grip® Clevis Anchorage – Technical Data
(forces calculated with strands 0.62" St 1660/1860)

             Cable type*                     DG-P 4       DG-P 7   DG-P 12 DG-P 19 DG-P 31 DG-P 37 DG-P 43 DG-P 55 DG-P 61
             No. of strands                        4        7         12          19         31            37          43              55             61

                                                                    Forces [kN]**
     Ultimate load at 100% GUTS                   1,116    1,953     3,348       5,301      8,649        10,323       11,997       15,345         17,019
     Service load at 50% GUTS
                                                  558      977       1,674       2,651      4,325        5,162        5,999        7,673          8,510
           for stay cables
     Service load at 60% GUTS
                                                  670      1,172     2,009       3,181      5,189        6,194        7,198        9,207          10,211
      for extradosed tendons

                                                                   Dimensions [mm]
             Clevis                  ØA           150      200        246         290        351          390          432          463               493
         Clevis length                B           350      385        436         528        616          667          720          810               838
             Clevis                   C            67       82        105         136        170          191          211          239               252
         Gusset plate                 D            88      108        136         177        221          241          264          301               311
               Pin                   ØE            52       67         85         115        138          150          170          195               202
         Gusset plate                 F            52       63         90         100        125          140          160          175               195
      Gusset plate hole              ØG            54       69         87         117        140          152          172          197               204
         Distance of
                                      H           400      510        740         940       1,210        1,360        1,550        1,610          1,780
      compaction clamp
       HDPE sheathing                ØP            63       90        110         125        160          180          200          200               225
 HDPE transition tube, clevis        ØS           110      140        200         225        250          315          315          315               355
* Bigger size on special request
** Load design guidelines have to be considered

                                                                                                                                                           15
DYNA® Link Anchor Box System

The DYNA® Link Anchor Box System
is based on a conventional steel
structure in which stay cables are
anchored with standard DYNA Grip®
anchorages. The DYNA® Link curved
Anchor Box is economically designed
using conventional steel construction
standards to ensure capacity,
serviceability and excellent fatigue
characteristics. Differential forces are
transferred to the concrete by shear
studs in regular design, which are
welded to the outer surface of the
Anchor Box flanges.

Advantages in Comparison to Conventional Pylon Solutions
The DYNA® Link Anchor Box features         ■■ When using DYNA® Link Anchor                ■■ Total cost and construction time of the
many advantages in comparison to              Boxes, pylon dimensions can be                 pylon can be reduced.
conventional pylon solutions in which         significantly reduced by eliminating        ■■ Easy and fast installation of box and
cables are anchored inside the pylon          anchorages inside the pylon. This              stay cable with minimum manpower
section:                                      allows slender and aesthetical pylon           during cable installation.
                                              shapes.
                                                                                          ■■ The horizontal load can be transferred
                                           ■■ The pylon does not need to be hollow           directly through the DYNA® Link
                                              to allow access for installing, stressing      Anchor Box with reduced stresses
                                              and servicing the anchorages.                  within the concrete.

DYNA® Link Anchor Box                                                                     Accessible Steel Box

 16
DYNA® Link Anchor Box System

Advantages in Comparison to Conventional Saddle Solutions
The DYNA® Link Anchor Box features many advantages in comparison to conventional saddle solutions in which strands are
guided through the pylon:

DYNA® Link                                                                    Conventional Saddle

      Topic                                         Description                                                       Conclusion
                      The use of conventional saddles results in equal strand numbers on
                      both sides of the tower for each cable. This outcome might not be the
                      most efficient or desirable from an economical and behavioral point of
                      view. This is evident for end spans that have a considerably larger stiff-
                                                                                                     With the DYNA® Link Anchor Box, the stay
                      ness than adjacent main spans and particularly for cables anchored
                                                                                                     cable assembly is flexible. Different cable
                      close to end supports.
  Bridge Design                                                                                      sizes can be used, and the effective cable
                                                                                                     length with a working point at the anchorage
                      There is also uncertainty on what is the effective cable length to be used
                                                                                                     is clearly defined.
                      in the structural analysis. This uncertainty stems from the fact that a
                      certain length of the curved strands inside the saddle will be subjected
                      to varying axial strains. This effect may be significant for the shorter
                      cables of Extradosed bridges.

                      Slip in conventional saddles is prevented by friction between the strands
                      and the saddle. Current design recommendations (such as PTI recom-
                      mendations and fib Bulletin 30) require that the friction factor be derived
                      from tests on specimens representing the parameters of the actual sad-
                                                                                                     By means of the DYNA® Link Anchor Box,
                      dles. These tests are conducted in the laboratory in dry and controlled
                                                                                                     the full cable force can be reliably taken at
                      conditions. Due to possible contamination or condensation, the condi-
                                                                                                     each side of the pylon. There is no limitation
                      tions in an actual saddle on site may be quite different from the test
                                                                                                     by a friction factor and there are no uncer-
                      conditions. This creates uncertainty as to the actual friction factor avail-
                                                                                                     tainties of friction at different climatic condi-
                      able to resist differential cable forces during the construction and ser-
Friction Factor and                                                                                  tions. Friction tests and additional slip limit
                      vice stages of the bridge.
  Slip Limit State                                                                                   stage investigations within the structural
                                                                                                     computation are not required.
                      Slip of strands inside a saddle must be completely avoided. This is an
                      additional limit state that must be investigated and verified by the bridge
                                                                                                     DYNA® Link Anchor Boxes can even be used
                      designer. This limit state is not related to the strength of the cable com-
                                                                                                     in seismic regions where friction type saddles
                      ponents, but depends on the friction between strand and saddle and
                                                                                                     are not recommended.
                      the magnitude of the cable forces at both ends of the saddle. Additional
                      load cases and combinations may need to be investigated using
                      advanced analytical methods, to ensure that this limit state would not
                      be violated.

                                                                                                     At the DYNA® Link Anchor Box, the strands
                      Due to the curvature of saddles, bending and transverse stresses are           are not deviated along the saddle. Therefore,
   Bending and        transferred to the strands. The bending stresses will reduce the axial         the fatigue performance and durability is not
    Transverse        strength of the strands. The transverse stresses may result in fretting        compromised, and existing full size fatigue
     Stresses         effects between the strand wires or between the strands and the saddle         and leak tightness tests of DYNA Grip® stay
                      that will result in reduced fatigue strength of the strands.                   cable tests can be used. Furthermore, there
                                                                                                     are no limits in the respective saddle radii.

                                                                                                                                                    17
DYNA® Link Anchor Box System

Advantages to Conventional Saddle Solutions

      Topic                                      Description                                                    Conclusion
                    The use of cable saddles results in doubling the man power and equip-
                                                                                               The DYNA® Link Anchor Box provides full
                    ment required for the installation and stressing of cables. In addition,
                                                                                               flexibility for the construction cycle, as cables
     Bridge         saddles require the pace of cantilever construction on both sides of the
                                                                                               may be installed alternately so that the over-
   Construction     tower to always be symmetrical before a cable may be installed. This
                                                                                               all construction time can be significantly
                    results in increased construction costs and inefficient utilization of
                                                                                               reduced.
                    resources.

                    Saddles do not allow the inspection of strands inside them. This may be
                                                                                               The durability of the DYNA® Link Anchor Box
                    critical because the strands are anchored by friction inside the saddle
                                                                                               is not compromised, as there are no strands
                    pipes and are subjected to multi-axial stresses and differential move-
                                                                                               which are deviated. Window opening at the
 Cable Inspection   ments due to live and dynamic loads.
                                                                                               DYNA® Link Anchor Box allows easy access
 and Maintenance
                                                                                               for inspection and maintenance. It is even
                    These conditions may adversely impact the design life of the strands
                                                                                               possible to replace a complete strand bundle
                    and their corrosion protection system; and this uncertainty may not be
                                                                                               only on one side of the pylon.
                    acceptable to bridge owners.

 18
DYNA® Link Anchor Box System

Stay Cable Installation
Depending on the pylon dimensions and
cable layout, the DYNA® Link Anchor
Box may either be provided with a
lateral or a top access at the pylon
interface for stay cable installation.

Standard solutions for both options
have been designed for each cable type
using Finite-Element Analysis software
with the following design assumptions
which are based on SETRA:

All standard solutions can be adapted
easily to any project specific demand,
and thus, the actual pylon dimension,
cable angles as well as design loads will
be taken into account.                          Von Mises stresses of a DYNA® Link Anchor Box with lateral access

Lateral Installation opening for DYNA Grip® Stay Cable Anchorage         Open top Installation opening for DYNA Grip® Stay Cable Anchorage

                    Type                                           Load Level                                  Deviation
             ULS DESIGN LOAD                                       90 % GUTS                            + 25 mrad deviation angle
                                                           45 % resp. 60 % GUTS
              SLS DESIGN LOAD                                                                           + 25 mrad deviation angle
                                                        (stay cable resp. extradosed)
                                                           200 MPa at 45 % GUTS
              FLS DESIGN LOAD                                                                              + 10 mrad deviation
                                                        resp. 140 MPa at 60% GUTS

                                                                                                                                       19
Saddle Solution

Saddle with Individual Tubes
If strands need to be guided through the    ■■ Individual strands can be replaced
pylon structure and a transfer of forces    ■■ Differential forces are transferred by
by friction is required, DYWIDAG offers        friction
a saddle in which the strands are guided
                                            ■■ Application of Epoxy coated strands
from one side of the pylon to the other:
                                               and consequently:
■■ Strands are placed into a multitude of      ■■ no peeling of strands’ sheathing
   individual, curved recess tubes. The           within the saddle necessary                     Centering Plate
   interstices between the saddle tube         ■■ no pressure; the coating is therefore
   and the recess tubes are grouted               not in danger of being harmed, which
■■ The saddle itself is embedded into             can occur when using PE-sheathed
   concrete                                       strand

                                                                                    Solid Plate

 20
Saddle Solution

                     Interstices filled with Grout

 Individual, curved Recess Pipes

                                                     Curved Saddle Pipe

                                                                          21
Fully Grouted Solutions

DYNA Bond® Anchorage
The DYNA Bond® Anchorage consists              Additional Advantages
of a conical steel pipe (bond socket)
supporting a wedge plate in which the          ■■ Minimized bending effects at the           ■■ Easy fixation of external dampers
strands are anchored with high-fatigue            anchorage by placing an elastomeric           directly on the grouted stay pipe
3-part wedges. A ring nut is fitted on the        bearing inside the recess tube             ■■ A special patent protected sealing
threaded end of the bond socket and            ■■ Reliable corrosion protection for the         provision allows to grout the
distributes the cable force through a             sensitive anchorage area, as all voids        anchorage area only so that the free
bearing plate into the structure.                 in the anchorage zone are filled with a       length remains without grout
                                                  stable and robust filler
■■ During the construction period – prior
                                               ■■ Enhanced fire resistance and
   to grouting the bond socket – all the
                                                  protection against vandalism, impact
   applied loads are supported directly
                                                  loads and blast effects
   by the wedges.
■■ At the final state of construction, all
   additional loads (live loads, vibrations
   and earthquakes) are partly resisted
   by both wedges and grouted bond
   socket.
■■ DYNA Bond® Anchorages have an
   excellent fatigue resistance because
   the bond action in the bond socket
   substantially reduces the magnitude of
   the dynamic loads reaching the wedge
   anchorage. Fatigue tests have proven
   a stress range of up to 240N/mm2
   at an upper load of 45% GUTS and
   2 million load cycles.

                                                                                                       Boot

                                                                                 Elastomeric Bearing

                                   Ring Nut                      Strands

                        Spacer
                                              Filling Material

               Wedges                                                                                              HDPE
                                                                                                                   Sheathing

                                                                                            Recess Pipe

                                                                       Bond Socket

                                               Bearing Plate

         Cap               Wedge Plate

 22
Fully Grouted Solutions

Saddle with Anchor Groove and Pin
The saddle transfers differential forces via a shear nose with pin into the pylon concrete construction.

■■ Strands (without PE coating inside the        ■■ An inner, curved saddle pipe is guided        transferred via a shear nose (anchor
   saddle) are guided in a curved tube              through an outer recess pipe that is          groove – pin construction)
   and injected in the deviation area using         embedded into the concrete                  ■■ The strand bundle including saddle
   special grout                                 ■■ Differential forces in the stays at            pipe can be exchanged if necessary
                                                    both sides of the saddle are reliably
 Steel Saddle Pipe

                       Steel Recess Pipe
        Grout

                                Strands (without PE sheathing
                                within the saddle area)

                 Anchor Pin

       Anchor                 Strands
       Groove

                              Exit Pipe

                     HDPE Sleeve

HDPE Sheathing

                                                                                                               Steel Recess Pipe
                                                                                                               with Anchor Groove

                                                                                             Steel Saddle Pipe with Anchor Pin

                                                                                  Grout

                                                                                                                                     23
Strand and Wedge

DYWIDAG Stay Cables use strands               Epoxy Coated Strands
that meet the requirements of fib and
PTI-Recommendations for stay cables,          ■■ Epoxy coated strand is manufactured        ■■ Epoxy material reduces fretting action
ASTM, BS as well as other national or            in compliance with ISO 14655:1999 or          between the individual wires and
international standards.                         ASTM A882. The 3-part wedges are              cushions adjacent strands in deviation
                                                 specially designed for epoxy coated           areas. It avoids damages within the
Generally, the following types of strands        strands. The teeth penetrate through          sensitive wedge gripping area and
are used:                                        the coating so that they grip into the        retains its properties as corrosion
■■ 7 cold-drawn galvanized wires                 wires of the strand.                          protection barrier
■■ PE-sheated with minimum thickness          ■■ Fatigue tests conducted on single-         ■■ The excellent bond of the epoxy
   of > 1.5mm in accordance with fib             strand tendons have proven a                  with the steel wires and the ductile
   Bulletin 30                                   dynamic stress range of up to                 behavior of the epoxy material avoids
                                                 260N/mm2 (upper stress 0.45 GUTS at           damages within the sensitive wedge
■■ Wax as a void filler for the interstices
                                                 2 million load cycles).                       gripping area and retains its properties
   between wires and PE sheathing
                                              ■■ Cold-drawn 7-wire strand is coated            as a corrosion protection barrier
■■ Diameters up to 0.62" and steel
                                                 with epoxy resin in the shop               ■■ An additional PE sheathing on top
   grades up to 1,860N/mm2
                                              ■■ Interstices between the 7 wires are           of the epoxy coating is possible,
■■ Low relaxation strand                                                                       protecting strands from damage
                                                 completely filled with epoxy resin, thus
■■ Strands are anchored with specially           providing excellent and robust long-          during handling and on-site installation
   treated 3-part wedges that are                time corrosion protection.
   characterized by high fatigue
   resistance.

Wedge for Galvanized Strand

Wedge for Epoxy Strands                                                                     Epoxy Coated Strand

 24
Strand and Wedge

Outer Stay Pipe
Standard Pipe

■■ HDPE pipes serve as protection
   against environmental influences
   and are typically used as outer
   covers of DYWIDAG Stay Cables.
   Main characteristics:
■■ Wind load reduction at the cable
■■ Outer helix with demonstrated
   efficiency against rain-wind induced
   cable vibrations
■■ Co-extruded or fully colored pipes
■■ Wide range of colors                   Standard Duct
■■ The excellent UV-resistance has been
   proven in accelerated aging tests
■■ Steel or stainless steel pipes are
   available on special request

Slim Duct

■■ For long span bridges, lateral wind
   loading at the cables needs to be
   taken into account for pylon design.
   To reduce the wind load, DSI offers
   slim sheathing with reduced pipe
   diameters.                             Slim Duct

                                          HDPE Sheathing with Helix

Stainless Steel Duct

                                                                      25
Cable Damping

Slender supporting structures and           Depending on the respective cable          By experience, DSI recommends to
long cable lengths make stay cables         parameters, each cable is more or less     increase a cable’s inherent damping by
susceptible to vibrations. Big vibration    prone to vibration. Longer cables are      using additional damping devices for
amplitudes may result in damages to the     more likely to vibrate than short ones.    cable lengths above 80m.
cable due to bending and fatigue loads.     Nevertheless, cables with lengths above
This decreases a cable’s d­ urability and   200m have been installed without           Cables start vibrating when they are
may even endanger structural safety.        additional dampers without any vibration   excited. Please find following some
                                            problems. On the other hand, even very     excitation causes and methods for
                                            short cables sometimes need dampers.       mitigating their effects.

 26
Cable Damping

   Excitation Causes
   Buffeting                                   Wake Galloping                                     Parametric Excitation

   ■■ Wind causes drag, lift and moment        ■■ Wake Galloping occurs at cables that            ■■ Parametric excitation is caused if the
      forces on cables that result in             are closely spaced in wind direction.              excitation acts on other parts of the
      cable vibrations. Depending on              Vortexes behind one cable excite the               structure (such as the pylon), and if
      the boundary conditions, inherent           cable that is next to it and lead to               this vibration is transferred into the
      damping of a stay cable without             vibrations.                                        cables.
      additional damping might not be high                                                        ■■ DSI not only supplies the appropriate
      enough to decrease these vibrations      Iced Galloping                                        damping devices but also supports
      to an acceptable amplitude.                                                                    bridge designers and owners in
                                               ■■ Ice that sticks to a round cable can               choosing a damping concept that is
   Vortex-Shedding                                alter its cross section in such a way              customized to their specific project
                                                  that galloping occurs above a critical             needs.
   ■■ Uniform wind flow causes turbulent          wind speed.
      vortices to detach, alternating from a                                                      Outer Helical Fillet
      cable’s top and bottom side, so that     Rain-Wind induced Vibrations
      vibrations are caused. The amplitudes                                                       ■■ To mitigate rain-wind induced
      are usually small compared to the        ■■ During specific combinations of rain               ­vibrations, a double helical fillet is
      cable diameter. However, resonance          intensity, wind speed, wind direction               applied on the surface of outer stay
      of the vortex shedding frequency and        and cable inclination, water rivulets               pipes
      cable eigenfrequencies can result in        arrange at the cable’s top and bottom
                                                                                                  ■■ Different diameters have been tested
      larger amplitudes.                          surface. Due to wind, they move
                                                                                                      in climatic wind tunnel tests
                                                  a few degrees around the cable
   Galloping                                      circumference and induce vibrations             ■■ Demonstrated drag coefficient of
                                                  into the cable. This happens at                     CD = 0.6 for large cable diameters
   ■■ Galloping affects rectangular shapes        relatively low wind speeds.
      or round shapes with asymmetry.
      If the wind speed is above a critical
      value, vortexes detach from the edges
      and create similar effects as vortex
      shedding. However, contrary to vortex
      shedding, galloping results in high
      amplitude vibrations.

   Drag Coefficient for Stay Pipe

                      0.8
Drag coefficient CD

                      0.7

                      0.6

                      0.5
                            0.5   1.0   1.5    2.0          2.5            3.0              3.5        4.0           4.5          5.0      5.3
                                                               Reynolds number Rc                                                        x105
                                                                  α = 0°         α = 180°

                                                                                                                                         27
Cable Damping

Damper Design
■■ Sufficient damping prevents cables            Correlation of
   from vibrating. DSI recommends                Achievable Damping Coefficient, Damping Ratio and Scruton Number
   damping values of at least 3–4%
   logarithmic decrement δ to be                                    1.25                                                                   16.5
   reached for the first two to three
   vibration modes depending on each
   cable’s boundary conditions and on                               1.00                                                                   13.2
   project specific requirements. These

                                              Damping Ratio ζ [%]

                                                                                                                                                    Scruton Number Sc
   damping values can usually not be
   achieved by inherent cable damping                               0.75                                                                    9.9
   so that additional damping is required.
■■ External viscous dampers provide very
   effective supplementary damping.                                 0.50                                                                    6.6

■■ Special software developed for DSI
                                                                    0.25                                                                    3.3

External Viscous Damper
                                                                      0                                                                         0
■■ Efficient dampers can be computed                                       0            400        800            1,200        1,600   2,000
   for each cable taking into account                                                                    c [kN* s/m]
   several vibration modes                                                     Mode 1         Mode 2          Mode 3         Mode 4    Mode 5
■■ In plane, the damper is sufficient to
   also suppress out of plane vibrations
■■ Slender and aesthetic design;
   ­available in several colors

                                                                                 Vandalism Protection Pipe

                                           Compaction Clamp

                                                                                                   External Viscous Damper

 28
Cable Damping

                                                               Vandalism Protection Pipe

                                           Exit Pipe

                          Compaction Clamp

                                                                        Internal Viscous Damper

                                           Flange Connection with
                                           high-strength Bolts

Internal Viscous Damper

In addition to external viscous dampers, DSI also offers internal viscous dampers
                                                                                                  Vandalism
that are attached to the exit pipe.                                                               Protection Pipe

■■ Damping forces are transmitted from       ■■ Since DSI housed dampers do not
   the damper through its steel housing         require a connection point on deck,
   and exit pipe into the recess pipe,          they can be used at virtually any cable
   from where they are transferred into         position
   the superstructure                        ■■ Increased durability is a benefit of
■■ Housed dampers are advantageous              housed dampers: they are not affected
   due to their avoiding additional             by weathering
   support structures for connection to      ■■ A stiff flanged connection is required
   the bridge deck
                                                                       Exit Pipe
Internal Rubber Damper
                                                            Compaction Clamp
Especially used for short and medium
cable lengths                                Flange Connection with                                    Internal
                                             high-strength Bolts                                       high efficiency Rubber Damper
■■ Internal rubber dampers are placed
   inside the exit pipe parallel to the
   cable axis
■■ Their elastomeric high efficiency
   material dissipates vibration energy
   while deforming when subject to shear
   stress

                                                                                                                               29
Full Size Testing

DYWIDAG Stay Cables have been               Standard Fatigue and Tensile Testing
successfully tested in numerous static
and fatigue tests in compliance with fib,   ■■ Applying 2 million load cycles   DYWIDAG Stay Cable testing has
SETRA and PTI recommendations. Tests        ■■ Stress range of 200N/mm²         also been successfully conducted in
have been conducted in collaboration                                            additional full size tests with increased
                                            ■■ Upper load level of 45% GUTS
with renowned Universities such as                                              requirements in terms of upper load and
CTL, TU Munich, TU Vienna, MPA              ■■ Inclined anchorages of 10mrad    additional angular deviation of the cable
Braunschweig or DTU Copenhagen.                                                 system.

              SETRA

Fatigue and Tensile Testing with higher load level and additional Transverse Deflection
■■ Application of 2 million load cycles
■■ Stress range of 100N/mm²
■■ Upper load level of 60% GUTS
■■ Anchorages inclined by 10mrad
■■ Deviation of ± 25mrad in transversal
   direction

 30
Fire Protection

Fatigue and Tensile Testing with additional Transverse Deflection (Setra)
■■ Applying 2 million load cycles
■■ Stress range of 200N/mm²,
■■ Upper load level of 45% GUTS
■■ Transverse deflection resulting in
   cyclic angular deviation from
   0 to 10mrad

Increased Load Cycle Testing – 10 Million Cycles
■■ Application of 10 million load cycles
■■ Stress range of 200N/mm²
■■ Upper load level of 45% GUTS
■■ Anchorages inclined by 10mrad

                                                                            31
Full Size Testing

Monostrand Fatigue Testing under Reversed Cyclic Flexural Loading
A series of bending fatigue tests on                            ■■
­galvanized, waxed and PE-coated 7
 wire strands 0.62" with an ultimate
 tensile strength of 1,860N/mm² were
 successfully performed. They proved
 that the standard protective measures of
 the sealing unit within the DYNA Grip®
Anchorage are effective for fatigue
bending without the additional use of a
guide deviator.

■■ Application of 2 million load cycles
■■ Different upper load levels varying
   from 45% to 60% GUTS
■■ Static inclination at the anchorage
   between 0.6° and 3.0°
■■ Additional angular deviation at the
   center of the strand between ± 10mrad
   and ± 35mrad

 32
Full Size Testing

Leak Tightness Test
DSI anchorages are fully resistant to any
infiltration of water. Tested according to
PTI requirements:
■■ Subsequent to fatigue testing
■■ For 96 hours
■■ With a 3m water head

And tested according to fib and Setra
requirements with:
■■ Up to 3m water head
■■ Several longitudinal and transverse
   load cycles
■■ Temperature cycle 20°C – 70°C

                                             33
Cable Installation

DSI has developed various methods to
optimize and simplify cable installation
procedures depending on site specific
space and time constraints.

■■ The outer sheathing is welded to its
   required length directly on site using
   heated tool welding and is then lifted
   into an inclined position
■■ Strands are uncoiled either from
   wooden reels or are provided reel-less.
   They are installed and stressed one by
   one using lightweight equipment
■■ Strand installation is performed using
   small winches or pushing devices
■■ Hardware configuration can be
   adjusted to site conditions to ensure
   a fast, customized solution that
   minimizes costs and cycle times
■■ Afterwards, strands are installed into
   the sheathing, and the complete cable
   is lifted into its final position
■■ Subsequently, all strands are stressed

If required, the complete cable can also
be preassembled on the ground first.

 34
35
Stressing

DYWIDAG stressing equipment is designed to ensure an economic and convenient installation process.

ConTen Stressing
The patented (EP2307637 B1;                        Change of Strand Force depending on t he Number of Stressed Strands
US8702066 B2) ConTen System uses a
monojack that is hydraulically coupled                                                       100,0

                                               Force in each Individual Stressed Strand of
                                               one Sequence after Stressing Strand i [kN]
with a control unit. The system is
applicable both for DYNA Grip® and                                                            90,0
DYNA Bond® Stay Cable Systems.
                                                                                              80,0
■■ Every single strand is stressed
   individually                                                                               70,0
■■ A special calculation method –
                                                                                              60,0
   developed by DSI – determines the
   force for the first strand and the
                                                                                              50,0
   ­corresponding forces for all ­sub­
    sequent strands                                                                           40,0
■■ This allows monitoring the stressing
    operation up to the required final cable                                                  30,0
    force                                                                                            0   10          20         30         40             50    60
■■ Equal forces are achieved in all                                                                            Number of Installed and Stressed Strands
    strands within one cable at the end of                                                               First Stressing Sequence       Second Stressing Sequence
    the stressing operation
■■ Influences of temperature and
    load changes during stressing are
    automatically eliminated

In case of very short strand elongation
values or if the cable force needs to be
adjusted, retensioning or releasing of the
complete cable is possible by turning
the ring nut. Special compact gradient
jacks are available for this purpose

■■ Gradient jacks may be moved fully
   assembled or disassembled into their
   main components so that they fit even
   through small openings
■■ The same economic type of hydraulic
   pump can be used for both stressing
   systems. The pump is light, robust and
   has proven its reliability in many stay
   cable projects

Standard Hydraulic Pump                            Gradient Jack

 36
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