2020 Pedestrian Tunnel Maintenance - Carnoustie Drive North of Aryshire Drive

The City of Dublin has programmed the removal of the existing deteriorated stone facade/slope face at both ends of the pedestrian tunnel located on Carnoustie Drive north of Aryshire Drive. Cast-in-place retaining walls are proposed to replace the existing stone facade retaining walls, which will require the existing mitered tunnel pipe ends to be removed and replaced with a standard 108-inch diameter concrete pipe, 8 feet in length - which is not mitered. The face of the retaining walls will be at the end of the standard concrete pipe. The proposed retaining walls will likely be a straight alignment. The retaining walls will have synthetic stone applied to exposed surfaces. The new pipe will have a concrete paved invert. The entire tunnel interior, both new and existing pipe, will be surfaced prepared, sealed, and painted on exposed surfaces. The existing timber guardrail on both sides of Carnoustie Drive will be removed and replaced with steel-back timber guardrail.

Division 02 -	Existing Conditions, Subsurface Investigation.
Division 31 -	Earthwork, Site Clearing, Grading, Excavation and Fill, Subgrade Preparation, Excavation, Shoring, Tunneling and Mining, Tunnel Excavation.
Division 35 -	Waterway and Marine Construction, Dam Construction and Equipment.