A14 Huntingdon Viaduct Strengthening

Client

Cleveland Bridge for Costain for Highways England

Project Description

The 1975 prestressed concrete viaduct carrying the A14 over the East Coast Main Line and a minor road has suffered from weak half joints in the main cantilever/suspended span for a number of years. In 2003 temporary strengthening of the joints was installed in the form of rows of underslung steel box beams with design life of 12 years. A more long term solution was pursued in 2013 due to changes in investment plans and the steel box beams were replaced by deeper, stiffer and heavier I beams. Installation of the new beams to the low headroom soffit of the concrete structure was not practical with cranes and novel techniques using a combination of heavy duty trailers, scissors lifts and fork lift trucks was used.

Cass Hayward Role(s)

• Three dimensional modelling of strengthening steelwork for the 2002 contract and preparation of drawings for fabrication
• Temporary works design for the lifting schemes for the 2013 steelwork installation

Project Statistics

• Completed August 2013
• Value £11m
• Beams increased in depth from 750mm to 1775mm
• Lifting weights of beam assemblies 21 tonnes

Special Features

• Internal anchoring steelwork in voids of concrete box girders detailed to accommodate significant variations in site dimensions and confined space working
• Lifting over railway possession
• Use of fork lift trucks
• Use of SPMT's with mounted with scissors lifts