The works will commence from 10pm on Monday 4 November.
The latest piling works have revealed that ground conditions are proving to be more challenging than initially anticipated for . To allow this key operation to be completed, and having consulted with the emergency services and Argyll & Bute Council, Transport Scotland has agreed to allow contractor McLaughlin & Harvey to extend the overnight road closure period by five nights.
This will see the closure run to 16 November.
The road will reopen each day at 6am and close at 10pm each night during the works.
Dominic Murphy, Transport Scotland Project Manager said: "I would like to take this opportunity to thank the local communities and road users for their continued patience so far. It is unfortunate that we have had to extend this set of overnight closures, but in doing so this will enable the Contractor to undertake some of the most critical work prior to constructing the main road deck section of the new viaduct in 2014. Recent difficulties with the ground conditions reinforce the unique topographical and geological challenges faced at this location.
"However, we have been working closely with the contractor to develop and implement an innovative approach to the construction that allows us to keep the road open each day while the works are underway. We will continue to work with the Contractor to minimise disruption as far as possible in delivering these improvements."
The A82 will be closed at Pulpit Rock, south of Ardlui, between 10pm and 6am each night.
Diversion routes for through traffic are:
- northbound via the A83 at Tarbet, A819 and A85
- southbound via the A85 at Tyndrum, A819 and A83.
(JP/CD)