Scottish Trunk Road Network Maintenance Contract - South East Unit

Description

The Forth Road Bridge (FRB) is a long span suspension bridge which carries the A9000 over the Firth of Forth. It was opened in 1964 and is a Category A listed structure. The bridge consists of two approach viaducts and a suspension bridge which forms the main section of the structure. The main cables of the bridge are fixed into the ground at either end of the structure. This connection to the ground is housed by 4 No. concrete structures known as the anchorage chambers. The anchorage chambers are dehumidified to protect exposed suspension cables at these locations. Water ingress into the chambers has caused defects to the structure. Therefore, a series of investigations were conducted of the internals of the chambers to determine the defects present and to allow for a refurbishment design to be established. The scheme will require a contractor to conduct the following repairs in all four chambers: concrete delamination and spalling repairs, concrete crack injection, vacuum grouting, blasting/painting of the steelwork, removal and reapplication of existing waterproofing. In addition, several improvements to the chambers have been proposed including: replacement of existing wooden staircases with new galvanised steel design, concrete breakout of existing vents and replacement with new design, refurbishment of existing platforms within the chamber and upgrading of existing lighting system. Two of the chambers are designated confined spaces due to previous gas monitoring, which will require Contractor’s working methods to consider. The Contractor must have demonstrable experience of similar works. The Contractor must also be approved to the applicable sector schemes for these kinds of works.