e-mosty June 2017: Osman Gazi B. US Suspension. Hålogaland B. e-mosty June 2017: Suspension Bridges | Page 53

overall ranking and selection process. The selection
process included an interview with each prospective
bidder and a Best-and-Final Offer (BAFO). The
contracting method was lump sum. Kiewit
Corporation was awarded the contract and notice-to-
proceed was issued in 2012.
In terms of the contract documents, the drawings and
specifications were modeled after the successful
dehumidification systems AECOM designed for the
three bridges in the UK. The documents were then
adapted to US standards and further best practices
were incorporated.
The contract documents included a combination of
prescriptive and outline drawings and material,
technical and performance specifications. This model
best manages risk for all parties – owner, engineer,
and contractor – as well as promotes high quality
cable wrapping and sealing work required for a
successful dehumidification system.
3.2 Dehumidification System Layout
AECOM designed the critical components of the
systems including the location of the injection and
exhaust sleeves, which established the blowing length
in the cables.
The systems for both bridges were designed to
dehumidify the entire length of the main cables,
including the splayed strands and end sockets and
anchor plates within the anchorages. The schematic
layouts of the systems are shown in Figure 6.
Figure 6: Dehumidification system layout – Eastbound Bridge (bottom), Westbound Bridge (top)
2/2017