Pedestrian Tunnel Maintenance FY2023

To perform detail design of replacing deteriorated retaining walls on a pedestrian tunnel under Memorial Drive. This project is fully funded by the City of Dublin. The Division of Engineering is hereby requesting a proposal from multi-disciplined, professional engineering consulting firms to prepare detailed construction drawings for new retaining walls at the face of the existing tunnel. The majority of the design professionals involved with the project must be located in central Ohio. 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 Memorial Drive southwest of Berkshire Court. 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 and a minimum of 30 ft. in length. The retaining walls will have manufactured 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 Memorial Drive will be removed and replaced with steel-back timber guardrail. No temporary construction easements are necessary for this project. Existing right-of-way, existing easements, and the Muirfield Association Walkway Easement areas will be adequate for most of the construction staging and construction of the project. Additional right-of-entry agreements will be secured by the City from adjacent property owners for construction.

Dam/Tunnel, New Construction.

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.