DYWIDAG Multistrand Stay Cable Systems - DSI Civil
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
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 3
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
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
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
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
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
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
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
You can also read