The Experts below are selected from a list of 840 Experts worldwide ranked by ideXlab platform

J Eppell - One of the best experts on this subject based on the ideXlab platform.

  • deck replacement of the angus l macdonald suspension bridge
    Structures Congress 2014American Society of Civil Engineers, 2014
    Co-Authors: D Radojevic, J Eppell, K Kirkwood, P G Buckland
    Abstract:

    The Angus L. Macdonald Bridge, a major suspension bridge that crosses Halifax Harbour in Halifax, Nova Scotia, was opened for traffic in 1955. The bridge deck has reached the end of its service life, and the design of the new bridge superstructure and its replacement sequence have been completed. The entire suspended structure and hangers will be replaced sequentially during night closures while the bridge will be opened for traffic during daytime. The Erection sequence has been supported by sophisticated automated Erection analysis models which take into account the geometry of the existing bridge, positioning of the Erection Equipment on the deck, and necessary hanger and strand jack adjustments. Significant wind tunnel testing and analysis have been performed to ensure aerodynamic stability of the bridge during Erection and in its final condition.

  • Extending the Life of the Angus L. MacDonald Suspension Bridge
    2014
    Co-Authors: D Radojevic, P G Buckland, K. F. Kirkwood, J Eppell
    Abstract:

    The Angus L. Macdonald Suspension Bridge crosses Halifax Harbour and connects Dartmouth and Halifax in Nova Scotia, Canada. The bridge was opened for traffic in 1955. The overall length of the bridge, including approaches, is 1,347 m (4,419 ft), and the suspension bridge is 762 m (2,500 ft) long. After almost 60 years of service, the aging bridge deck is experiencing significant corrosion problems and is reaching the end of its service life. Therefore, the owner, Halifax Harbour Bridges, decided to replace the entire suspended superstructure including the hangers. Bridge inspections showed that all parts of the bridge that are not being replaced (main cables, towers, cable bents and foundations) are in good condition and expected to have a long life. The designs of the new bridge superstructure and its replacement sequence have been completed. Safety of the public and minimization of traffic disruption have been the central themes driving the design. The entire suspended structure will be replaced sequentially during night or weekend closures. The bridge will be open for traffic during each working day. An unusual feature of the project is that the Owner's Engineer performed a detailed step-by-step analysis of the Erection sequence, has designed some of the key Erection Equipment, and is providing necessary forces and adjustments to the Contractor for his use during Erection. The reason for performing analysis that is normally in the Contractor's scope is to reduce the risk to the owner in terms of cost and delays. Following the replacement of deck segments, the deck will be raised to increase the navigation channel clearance by 2.1 m at midspan. Dehumidification of main cables is being considered in order to extend their service life.

P G Buckland - One of the best experts on this subject based on the ideXlab platform.

  • deck replacement of the angus l macdonald suspension bridge
    Structures Congress 2014American Society of Civil Engineers, 2014
    Co-Authors: D Radojevic, J Eppell, K Kirkwood, P G Buckland
    Abstract:

    The Angus L. Macdonald Bridge, a major suspension bridge that crosses Halifax Harbour in Halifax, Nova Scotia, was opened for traffic in 1955. The bridge deck has reached the end of its service life, and the design of the new bridge superstructure and its replacement sequence have been completed. The entire suspended structure and hangers will be replaced sequentially during night closures while the bridge will be opened for traffic during daytime. The Erection sequence has been supported by sophisticated automated Erection analysis models which take into account the geometry of the existing bridge, positioning of the Erection Equipment on the deck, and necessary hanger and strand jack adjustments. Significant wind tunnel testing and analysis have been performed to ensure aerodynamic stability of the bridge during Erection and in its final condition.

  • Extending the Life of the Angus L. MacDonald Suspension Bridge
    2014
    Co-Authors: D Radojevic, P G Buckland, K. F. Kirkwood, J Eppell
    Abstract:

    The Angus L. Macdonald Suspension Bridge crosses Halifax Harbour and connects Dartmouth and Halifax in Nova Scotia, Canada. The bridge was opened for traffic in 1955. The overall length of the bridge, including approaches, is 1,347 m (4,419 ft), and the suspension bridge is 762 m (2,500 ft) long. After almost 60 years of service, the aging bridge deck is experiencing significant corrosion problems and is reaching the end of its service life. Therefore, the owner, Halifax Harbour Bridges, decided to replace the entire suspended superstructure including the hangers. Bridge inspections showed that all parts of the bridge that are not being replaced (main cables, towers, cable bents and foundations) are in good condition and expected to have a long life. The designs of the new bridge superstructure and its replacement sequence have been completed. Safety of the public and minimization of traffic disruption have been the central themes driving the design. The entire suspended structure will be replaced sequentially during night or weekend closures. The bridge will be open for traffic during each working day. An unusual feature of the project is that the Owner's Engineer performed a detailed step-by-step analysis of the Erection sequence, has designed some of the key Erection Equipment, and is providing necessary forces and adjustments to the Contractor for his use during Erection. The reason for performing analysis that is normally in the Contractor's scope is to reduce the risk to the owner in terms of cost and delays. Following the replacement of deck segments, the deck will be raised to increase the navigation channel clearance by 2.1 m at midspan. Dehumidification of main cables is being considered in order to extend their service life.

D Radojevic - One of the best experts on this subject based on the ideXlab platform.

  • deck replacement of the angus l macdonald suspension bridge
    Structures Congress 2014American Society of Civil Engineers, 2014
    Co-Authors: D Radojevic, J Eppell, K Kirkwood, P G Buckland
    Abstract:

    The Angus L. Macdonald Bridge, a major suspension bridge that crosses Halifax Harbour in Halifax, Nova Scotia, was opened for traffic in 1955. The bridge deck has reached the end of its service life, and the design of the new bridge superstructure and its replacement sequence have been completed. The entire suspended structure and hangers will be replaced sequentially during night closures while the bridge will be opened for traffic during daytime. The Erection sequence has been supported by sophisticated automated Erection analysis models which take into account the geometry of the existing bridge, positioning of the Erection Equipment on the deck, and necessary hanger and strand jack adjustments. Significant wind tunnel testing and analysis have been performed to ensure aerodynamic stability of the bridge during Erection and in its final condition.

  • Extending the Life of the Angus L. MacDonald Suspension Bridge
    2014
    Co-Authors: D Radojevic, P G Buckland, K. F. Kirkwood, J Eppell
    Abstract:

    The Angus L. Macdonald Suspension Bridge crosses Halifax Harbour and connects Dartmouth and Halifax in Nova Scotia, Canada. The bridge was opened for traffic in 1955. The overall length of the bridge, including approaches, is 1,347 m (4,419 ft), and the suspension bridge is 762 m (2,500 ft) long. After almost 60 years of service, the aging bridge deck is experiencing significant corrosion problems and is reaching the end of its service life. Therefore, the owner, Halifax Harbour Bridges, decided to replace the entire suspended superstructure including the hangers. Bridge inspections showed that all parts of the bridge that are not being replaced (main cables, towers, cable bents and foundations) are in good condition and expected to have a long life. The designs of the new bridge superstructure and its replacement sequence have been completed. Safety of the public and minimization of traffic disruption have been the central themes driving the design. The entire suspended structure will be replaced sequentially during night or weekend closures. The bridge will be open for traffic during each working day. An unusual feature of the project is that the Owner's Engineer performed a detailed step-by-step analysis of the Erection sequence, has designed some of the key Erection Equipment, and is providing necessary forces and adjustments to the Contractor for his use during Erection. The reason for performing analysis that is normally in the Contractor's scope is to reduce the risk to the owner in terms of cost and delays. Following the replacement of deck segments, the deck will be raised to increase the navigation channel clearance by 2.1 m at midspan. Dehumidification of main cables is being considered in order to extend their service life.

Jing Tao - One of the best experts on this subject based on the ideXlab platform.

Max Meyer - One of the best experts on this subject based on the ideXlab platform.

  • under slung and overhead gantries for span by span Erection of precast segmental bridge decks
    Structural Engineering International, 2011
    Co-Authors: Max Meyer
    Abstract:

    Decks that are made self-supporting span by span are by far the most common structural systems used for precast segmental viaducts. Unlike other systems the contractor has little choice than to use overhead or under-slung gantries when erecting such viaducts, unless it is possible to utilize ground-supported falsework. Decks are activated span by span by stressing all segments of a span together with longitudinal prestressing cables, which run the full span length. Because such gantries need to be able to support the weight of an entire span, they are among the heaviest Erection Equipment used for bridge construction. The method by which segments are joined and activated to self-supporting spans has a direct impact on gantry's performance criteria and configuration. The designer should understand the detail of how such bridges are built, as many design and detailing aspects are governed by construction considerations and not by in-service requirements. The contractor, when ordering a gantry, needs a good understanding of how the bridge, he/she has to build, works structurally to enable him/her to order the right Erection Equipment. This paper starts with a classification of the precast segmental bridge decks built span by span. It subsequently explains the main features of typical under-slung and overhead gantries and compares their application ranges. The interaction between Erection Equipment and permanent works is highlighted followed by comments about design/detailing of main girders, mechanization and work access, risks and cycle times. It concludes with remarks about reusability and guidelines for ordering such gantries.