A9 Kincraig to Dalraddy
This project involved the construction of a dual carriageway along the section of existing trunk road between Kincraig and Dalraddy, as part of an overall systematic upgrade of the A9 dualling separating Perth and Inverness in Scotland. ByrneLooby was commissioned by the design and build contractor to act as the temporary works designer for online widening of approximately 8km of the A9. The specific remit for the temporary works solutions involved the demolition of six underpasses beneath the existing road followed by reconstruction of new structures to accommodate the upgraded dual carriageway.
A major constraint on the project was the requirement for the existing single carriageway road to remain open to traffic at all times. Costly lane closures required the design solution to minimise lane closure in order to keep the project cost down. ByrneLooby devised a solution which involved sequential temporary works, comprising combinations of reinforced earth, soil nailing and bored pile anchored retaining walls to maintain traffic flow while the bridges were demolished, extended and improved and the carriageway widened, all within a tightly constrained work site.