Strengthening and refurbishment of Severn Crossing, part 3: construction

The strengthening and refurbishment of the structures of the Severn Crossing were undertaken in various contracts in the period 1985-91 during which the route was maintained as fully operational. The paper describes the organization of the work on site and the procedures adopted to safeguard against accidental damage and injury. Constructional methods used in the more complex parts of the work are summarized, including hanger replacement procedures. The operations of jacking the Severn Bridge towers and of replacing the Wye Bridge stays and the associated monitoring systems are described. The strengthening of Aust viaduct and the construction of ship collision protection to piers of the viaduct and Wye Bridge are also described. Steelwork installation and welding problems are discussed. The procedures for resurfacing of the roadway decks are outlined. (A)