If the structure can be shown to have a 40t assessment live load rating, without the need for major strengthening, the financial benefits to our client will be significant.
Joe Kelly

Joe Kelly

Technical Director
Client
Skanska UK
Location
Birmingham, UK
Market

Summary

Roughan & O'Donovan was commissioned by Skanska UK to conduct a load capacity assessment of the bridge, with the aim of helping the bridge owner to minimise risk and achieve value for money by avoiding unnecessary strengthening.

Background

Navigation Street Bridge is a 1960’s bridge consisting of concrete-encased steel beams, reinforced concrete slabs, pre-tensioned and post-tensioned concrete.

Solution

Our review of the many assessments conducted on the structure between 2004 and 2013 identified a number of opportunities to increase the live load rating, including:

  • Consideration of worst credible strengths from testing performed on the bridge
  • Application of k-factors from BD21/01 to the Annex D assessment vehicles
  • Re-evaluation of the dead load/geometry
  • Refinements of the structural modelling

These opportunities may allow the structure to be reassessed deterministically, with the further possibility of a detailed probabilistic assessment as part of stage 2.

Challenge

Minimising physical works on a structure located at a critical intersection, over the main railway line in the very busy city centre, represented our key challenge.

Services provided:

  • Bridge engineering design
  • Risk assessment