Cable Anchorages Research Articles

Novel bamboo-raft-type floating structure (BRT-FS) assembled by FRP reinforced concrete tubes: Conceptual design and analysis

To improve construction efficiency in offshore engineering and extend service life of offshore platforms, a novel bamboo-raft-type floating structure (BRT-FS) assembled by FRP reinforced concrete tubes is proposed. It comprises four fundamental components: concrete tube, carbon fiber-reinforced polymer (CFRP) cable, holding beam, and bellow. This paper presents the structure system and structure design of BRT-FS. Separating load-bearing and buoyant functions ensures structural safety and ease of design. It has broad application perspectives in offshore construction due to its high corrosion resistance, designability, construction efficiency, and low crack control requirement. Furthermore, to obtain the operation conditions of BRT-FS, the mechanical performance is analyzed from two levels, which are hydroelastic analysis and structural analysis. Hydroelastic analysis is conducted under different wave directions, wave periods, water depths, and structural dimensions using a new finite element-boundary element (FE-BE) method. In a specify study case, a sensitive period around 11 s for head sea, around 7 s for oblique wave, around 5 s for beam sea are noted. The hydroelastic response is not significantly affected by water depth or transverse dimension. Structural analysis indicates that the structure can work in clam harbour sea with breakwater protection. Even after concrete tubes crack in higher waves, this new structure can still float with the inside bellows in theory. These preliminary findings confirm the feasibility of this novel structure. Structural details such as tube-tube joints, tube-beam joints, CFRP cable anchorages, and other connections will be further designed and tested in the future.

Kosciuszko Bridge, USA: New York City's first cable-stayed highway bridge

The Kosciuszko Bridge carries a 1.8 km long segment of the Brooklyn–Queens Expressway over Newtown Creek between Brooklyn and Queens in New York City, USA. The roadway is a vital link in the region's transportation network, carrying over 170 000 vehicles/day. Owing to structural and operational deficiencies, the existing structure was replaced. The new bridge consists of two parallel structures, one eastbound and one westbound, with main spans mirroring one another. Each structure consists of a single-tower cable-stayed main span over Newtown Creek with unbalanced main and back spans. This was the first cable-stayed bridge to be constructed in New York City, joining the ranks of the city's most iconic bridges. Here, two main span structures are discussed, with the focus primarily on the design and construction of the westbound, phase 2 bridge. Some key design aspects are outlined, including outboard cable anchorages, a concrete-filled counterweight and other details intended to facilitate construction, maintenance and inspection. The eastbound, phase 1 bridge was constructed under a design–build contract, and the westbound, phase 2 bridge as a design–bid–build. The paper also touches on some of the design aspects that were refined during the second phase.

Development and Testing of a Tool to Create Multiple Conical Reamed Cable Bolt Anchorages in Weak Rock

Development and Testing of a Tool to Create Multiple Conical Reamed Cable Bolt Anchorages in Weak Rock

Method for investigating the reliability of structural elements of cable-stayed supports' anchorage: a case study of the Russky Bridge

This paper presents the manufacturing technique, anchoring efficiency, design concept, and anchoring analysis of the Russky bridge anchor cables. Cable anchorages are one of the most critical components of a cable-stayed bridge, which has a complicated construction and bears significant weight. The bridge route can handle over 50,000 cars per day. The backstays and cable anchorages of the Russky bridge play a dominant role in ensuring the overall stability of the structural system. The backstay helps stabilize the end of the pylon because it anchors the pylon back toward the side span when the main span is carrying a live load. The backstay and anchorage forces are increased by the live load q on the main span. When the live load q occupies just the side span, the backstay forces are reduced to a minimum. In comparison to all other cables, the backstays and anchorages are subject to the most stress variations/amplitudes. In this paper, a method will be developed to determine the dimensions and forces at the anchorage point of stay cable under dead load (internal force balanced method) where the stress differences are safely less than its fatigue strength. by disregarding the bending stiffness of the deck and that all stay cables crisscross at the top of the pylon head.

The Third Bosphorus Bridge: A Milestone in Long-span Cable Technology Development and Hybrid Bridges

The Yavuz Sultan Selim Bridge is a high-rigidity suspension bridge, combining stiffening stay cables and suspension cables. It features a 1408 m central span, and supports a railway and a motorway with a 58.5 m wide deck between stiffening stay cable anchorages. The design of the stiffening stay cables for this bridge required several developments to cater for the exceptional needs of the longest and heaviest stay cable in the world. The usual strand grade would not meet the project forces and 1960 MPa strands had to be qualified, for all the anchorage units within the range, up to 151 strands. Such qualification is, however, only the tip of the iceberg as many other tailor-made components had to be developed. Heavy-duty deviators needed to be proof tested for fatigue and wear and were a vitally important part of the design. Long-stroke hydraulic pistons had to be qualified for performance, long-term resistance to corrosion and ageing.

Projekt konstrukcije staklene stijene ovješene na prednapetim kablovima

Na primjeru projekta izvedene staklene stijene ovješene na prednapetim vertikalnim kablovima, u radu su kratko opisane njihove konstrukcijske značajke, a detaljnije razrađena načela proračuna. Uspoređeni su rezultati primjene dvaju pristupa u modeliranju: integralnog, koji uključuje i glavnu nosivu konstrukcije te interakciju u zonama oslonaca ostakljenja, te pojednostavnjenog, sa sekvencijalno modeliranim kablovima i simulacijom interakcije s glavnom konstrukcijom oprugama zamjenskih krutosti u točkama sidrenja kablova. Analizirane su prednosti, razlozi i posljedice primjene modela na ponašanje staklene stijene i cjelovite konstrukcije.

The world's first extradosed bridge with corrugated steel webs: Japan's Ohmi–Odori Bridge

This paper describes the design and construction of Ohmi–Odori Bridge in Japan, which is the world's first multi-cell extradosed prestressed composite bridge with corrugated steel webs. Structurally, the bridge combines two new technologies: a composite prestressed concrete bridge with a corrugated steel web to reduce the dead weight of the main girder and an extradosed bridge to allow a longer span length. Several innovations were used on this bridge, including a three-cell box cross-section, adopted for the first time for the main girders of a bridge using corrugated steel webs, and a steel–concrete composite structure adopted for the cable anchorages. In 2006, the bridge was honoured with the highest award for a bridge project, the Tanaka Prize awarded by the Japan Society of Civil Engineers.

Yachihe Bridge, China: engineering the world’s longest cable-stayed steel truss

Yachihe Bridge in China is the longest steel-truss, cable-stayed bridge in the world and the tenth longest overall. Completed in 2016, its 800 m main span carries the new Guiyang–Qianxi dual carriageway over the Yachihe River gorge. It is also the first cable-stayed bridge to be erected using a cable crane, and its concrete-box-girder side spans feature the first use of cable anchorages in the middle of the outer web. Furthermore, geometry alignment during deck closure was achieved by adjusting cable forces rather than by using counterweights. This paper describes the configuration and numerical analysis of the innovative cable anchorage, discusses the challenges and solutions involved in using a cable crane for construction and details the novel closure techniques adopted for the steel-truss deck.

16.18: DYNA® link anchor box: Innovative structure for anchoring stay cables

ABSTRACTCable stayed and extradosed bridges are often designed with saddles at the pylon. This results in slender dimensions of the pylon and reduced costs as access shafts within the pylon can be omitted. However, inspection of the deviated strands within the saddle is only possible after exchanging single strands or the complete cable. Furthermore, differential forces in the cables are often transferred within the saddle by friction only. Also, cable installation and stressing have to be carried out simultaneously on both fronts of the form traveller for the most common balanced free cantilever construction method.To find an alternative solution for an improved performance of pylon design, installation cycle and cable inspection, a new curved anchor box has been developed. The DYNA® Link anchor box consists of two sections: in the concrete, there are two steel beams with shear studs for transferring the cable load into the concrete pylon; outside, the concrete the steel beams are connected to each other, and a bearing plate is welded to the steel beams as support for the cable anchorage. An opening at the steel beam provides access for installation and inspection of the cable anchorage. Through this steel anchor box, which is embedded in the solid concrete pylon, two stay cable anchorages are linked to each other and are located outside the pylon. With this design, all advantages of common saddles are kept; the disadvantages are compensated by using a steel composite structure which can be designed and calculated according to national or international standards. In doing so, elaborate testing in accordance to international cable guidelines such as fib or PTI can be omitted as well.

An experimental study on bond-type anchorages for carbon fiber-reinforced polymer cables

It is well-known that the axial performance of carbon fiber-reinforced polymer (CFRP) cables is excellent, while the lateral compression and shear strengths are low. Thus, traditional steel cable anchorages cannot be used for CFRP cables due to the local crushing failure mode that would develop. Hence, a new bond-type anchorage filled with resin was proposed and five CFRP cables were fabricated with the new anchorage, which were tested statically to failure in tension. The tensile capacity, bond strength and pullout behavior of the new anchorage for CFRP cables were observed experimentally and are presented in this paper. The load–slip behavior of the new anchorage, sustained loading effect, load–deformation curves and the stress variation between tendons in the cables are also presented and discussed. Tensile fracture of the tendons was observed for all the five cables tested with efficiency coefficients all greater than 1.00. The tensile strength and overall performance achieved by the anchorage and CFRP cable system satisfied the design requirements for use in an experimental cable-stayed bridge constructed in China.

Carbon Fiber Reinforced Polymer for Cable Structures—A Review

Carbon Fiber Reinforced Polymer (CFRP) is an advanced composite material with the advantages of high strength, lightweight, no corrosion and excellent fatigue resistance. Therefore, unidirectional CFRP has great potential for cables and to replace steel cables in cable structures. However, CFRP is a typical orthotropic material and its strength and modulus perpendicular to the fiber direction are much lower than those in the fiber direction, which brings a challenge for anchoring CFRP cables. This paper presents an overview of application of CFRP cables in cable structures, including historical review, state of the art and prospects for the future. After introducing properties of carbon fibers, mechanical characteristics and structural forms of CFRP cables, existing CFRP cable structures in the world (all of them are cable bridges) are reviewed. Especially, their CFRP cable anchorages are presented in detail. New applications for CFRP cables, i.e., cable roofs and cable facades, are also presented, including the introduction of a prototype CFRP cable roof and the conceptual design of a novel structure—CFRP Continuous Band Winding System. In addition, other challenges that impede widespread application of CFRP cable structures are briefly introduced.

Study on Long-term Anti-corrosion Technology for Bridge Cable Anchorages

Study on Long-term Anti-corrosion Technology for Bridge Cable Anchorages

Mounting Elements of Monolithic Linings1

Cable anchorages produced by OOO Stal’ 45 for use in mounting monolithic linings of heating plants are described. The basic characteristics of the anchors and the sequence used in mounting the anchors are presented.

Wind loads analysis at the anchorages of the Talavera de la Reina cable stayed bridge

This paper describes wind tunnel tests performed on wind tunnel models of the Talavera de la Reina cable stayed bridge. The work describes the aeroelastic model construction and it is focused on the evaluation and analysis of the mean and peak wind loads at the tower foundation and the cable anchorages since these data can be very useful by the bridge manufacturer as a support for the bridge design. The work is part of a complete wind tunnel study carried out to analyze the aeroelastic stability of the bridge.

Theoretical and Experimental Study on Cable-to-Irder Anchorages in Long-Span Cable-Stayed Bridges with Steel Box Girder

Cable anchorages are among the most important elements in a cable-stayed bridge, which are complex in structure and bear heavy load. There are three main forms in anchorage zone between girder and cable in modern long-span cable-stayed bridge with steel box girder, which are ear-plate form, anchor-box form and anchor-plate form. Combining theoretical analysis with the static test, static behavior and stress transfer pathway of three typical cable-to-girder anchorages were analyzed, and the differences of stress distribution and stress concentration among anchorage zones were pointed out. Based on the Von.Mises strength criterion, bearing safety of three typical cable-to-girder anchorages was evaluated. Finally, the measures to reform stress distribution and reduce stress concentration are discussed. Some useful conclusions were obtained, which would benefit the design of cable-to-girder anchorages.

The landmark Metsovitikos Bridge, Greece

Egnatia motorway in northern Greece is one of the largest civil engineering projects in Europe; Metsovitikos Bridge is one of its two landmark structures. A scheme incorporating a pier-less suspension bridge with inclined hangers was originally selected by the client through a design competition between three distinguished European firms of consultants. Despite the novelty and elegance of this scheme, its well-advanced design was abandoned due to uncertainties regarding the long-term stability of a landslip behind one of the cable anchorages. The design was subsequently replaced by a balanced cantilever bridge scheme with a main span of 235 m, believed to be the longest-span bridge of its kind in the Balkans. This paper explains the suspension bridge design, outlines its advantages and disadvantages, and describes the design and construction of the balanced cantilever bridge in some detail.

Analysis of in situ rock bolt loading status

It is well-known that the axial performance of carbon fiber-reinforced polymer (CFRP) cables is excellent, while the lateral compression and shear strengths are low. Thus, traditional steel cable anchorages cannot be used for CFRP cables due to the local crushing failure mode that would develop. Hence, a new bond-type anchorage filled with resin was proposed and five CFRP cables were fabricated with the new anchorage, which were tested statically to failure in tension. The tensile capacity, bond strength and pullout behavior of the new anchorage for CFRP cables were observed experimentally and are presented in this paper. The load–slip behavior of the new anchorage, sustained loading effect, load–deformation curves and the stress variation between tendons in the cables are also presented and discussed. Tensile fracture of the tendons was observed for all the five cables tested with efficiency coefficients all greater than 1.00. The tensile strength and overall performance achieved by the anchorage and CFRP cable system satisfied the design requirements for use in an experimental cable-stayed bridge constructed in China.

Höga Kusten Bridge, Sweden

The Höga Kusten Bridge is a suspension bridge with a main span of 1210 m, an overall length of 1800 m, and a minimum clearance under the main span of 40 m. Two environmental factors played essential roles in the design of the bridge: the beautiful landscape surrounding the bridge; and the winter climate in the region. Therefore, a conventional three-span suspension bridge from shore to shore was chosen, and special architectural treatment was given to the shapes of the pylons and the cable anchorages. Bids were only accepted if they were based on the bridge design developed by the Swedish National Road Administration.

APPLICATION OF ULTRASONIC TESTING FOR FATIGUE CRACK DETECTION OF BOLTS

Bolts and bolted connections are indispensable in most steel structures today. In civil engineering field, especially in bridge structures, bolts of large diameter are frequently used in very important portions such as shoes, expansion joints, cable anchorages and so on. Recently, accidents caused by fatigue failure of these bolts have been reported and importance of maintenance has been strongly noticed.This research is to establish reasonable non-destructive detection method for fatigue cracks of bolts in their service conditions. Two types of ultrasonic testing method were proposed and their detection performances of fatigue crack were examined by fatigue test of bolts. From this experiment, data on fatigue crack growth and fatigue life of bolts were obtained and accuracy of fatigue crack detection by proposed ultrasonic testing was confirmed. As the results, possibility of rational supervision system for bolts in use was shown.

Seismic Analysis Of A Combined Suspension And Cable Stayed Bridge System

This work presents the experimental and analytical evaluation of the Wheeling suspension bridge, a historic American landmark and the longest single span suspension system in the world for many years. The study was funded by the Federal Highway Administration and the West Virginia Department of Transportation to assess the condition of the structure and determine its response to selected seismic motions in order to recommend proper retrofit measures and possible strengthening of the bridge. The bridge is one of the few historic suspension bridges still in service in the U.S. The 307 m bridge deck is suspended by two main suspension cables assisted by diagonal stay cables. The stay cables are located within the end quarter spans, they pass over the saddles at each tower and are anchored into the main cable anchorages. The study includes in-situ testing of the cable system, validation of two- and three-dimensional finite element models to reflect the modal characteristics of the bridge, static analysis of the structure for code defined dead and live loads, and several seismic analyses using AASHTO seismic loads and historic earthquake data. The AASHTO seismic loads were modified to correspond to 10% probability of being exceeded in 100 years. The historic data were based on Mercalli intensity local earthquakes recorded in the early eighteenth century. Load rating indicated that none of the structural members are overstressed by the posted live load. The seismic analysis to AASHTO loads showed little damage that was confined to floor beams at the east tower. Analysis using historic earthquakes showed localized damage of floor beams and diagonal floor ties at the east tower and top chords of the stiffening truss at mid-span. The study concludes that the methodology can be applied to a wide range of cable suspension bridges.