Brief Description

Fehily Timoney Gifford carried out the detailed design for this scheme in accordance with the NRA DMRB and NRA Specification for Roadworks. Consisting of 10km of dual carriageway, regional and local roads and associated structures, the project included five major structures – three road overbridges, one road underbridge and one accommodation underpass.

This Design and Build contract started in May 2003 and was opened in October 2004, a full 7 months ahead of programme.

Notable Features

Roadworks
Fehily Timoney Gifford prepared the successful tender design on behalf of Roadbridge Ltd. We subsequently created the Detailed Design for all elements of the project, which comprised approximately 8km of National Primary Dual Carriageway and 2km of National Secondary Single Carriageway, as well as one grade separated junction and four at grade roundabouts. This was the first National Primary Road which incorporated a slip formed vertical concrete barrier.

Drainage
The Cashel Bypass goes through an area of Regionally Important Aquifer that required protection. Fehily Timoney Gifford devised a drainage design that ensured the protection of the groundwater from accidental pollution during construction and operation of the new road. A new 1.5km outfall was designed along with two attenuation ponds.

Overbridges
These bridges are three-span reinforced concrete structures with a typical span configuration of 14m, 31m, 14 m. Supports comprise integral in situ concrete intermediate piers and integral abutments with reinforced concrete wing walls. The abutments and central piers are supported on direct footings while the superstructure consists of prestressed concrete Y beams with an in situ reinforced concrete deck slab.

Underbridge
This reinforced concrete portal type structure, with a single-span of 12m, has a substructure consisting of in situ abutments, supported on a pad foundation. Its wingwalls are cantilevered from the abutments and its superstructure consists of prestressed Y beams with an in situ deck slab.

Accommodation Underpass
A reinforced concrete box type structure, the underpass is constructed from a number of precast box sections 1.5m long, with independent precast wingwalls.

Fehily Timoney Gifford Responsibilities

• Detailed Design
• Quality Management
• Value Engineering
• Preliminary Reports
• Site Supervision
• Section 50 approval procedures