M7
 

Name:   N7 Nenagh to Limerick High Quality Dual Carriageway - Design & Build Joint Venture
Client:   Limerick County Council   
Consultants:  RPS 
Location:  Parallel to the existing N7 from Nenagh to Limerick 
Project Value:  €175million 
Completion Date:  2010

Project Description:

Approximately 28 kilometres of a new motorway. The widening of the Nenagh Bypass (approximately 10km) to provide a Motorway. Approximately 2km of new single carriageway to link the proposed M7 to the existing N7 at Birdhill Grade separated junctions on the proposed M7 with all associated slip roads at Newport, Coolderry, Carrigatogher and Knockalton (Thurles Road) and realignment and upgrading of various single carriageway National Roads.

Regional Roads and Local Roads 

26 number Principle Structures including a 140m (approx) Viaduct at Kilmastulla, together with all other Principle and Minor Structures necessary as part of the Design and the works and also including various chambers and ducting works, various landscape, environmental and mitigation works, culverting and re-alignment of rivers and streams and the provision of drainage outfalls, fencing, safety barrier systems and drainage works,  various signing and lighting works, various earthworks works, various other works including diversions of the assets of Authorities, Utilities, Service Providers and Private Utility Services and the like, and various accommodation Works including accesses to properties and lands;

As part of their works Coffey Construction built 12km of th road. This inlcuded the interchange at Anacotty which had significant traffic management with AADT's of 20,000 being maintained at all times. there was also traffic mangement involved at the numerous side roads crossing the mainline. As part of the management team Coffey's were also responsible for the widening of 10km of the Nenagh bypass while maintaing traffic flows at all times

Structures:

Coffey Construction were responsible for the Design and construction of three number bridges as part of this contract.

Two Number road bridges constructed using reinforced earth structure were required over new motorway from Limerick  to Nenagh. Double span, bridges, 35m length and 5.0m height. Constructed Reinforce Earth Walls. The new embankments were graded and landscaped and the existing junction was re-alinged to tie into the new bridge structure. Public lighting was installed on the bridge and all the stationary utilities were diverted into the new services.
Irish Rail Bridge:The new build reinforced earth structures were required over the existing Limerick Nenagh Railway Line. Double span, Irish Rail bridge, 23m length and 3.0m height. Constructed Reinforce Earth Walls. Public lighting was installed on the bridge and all the stationary utilities were diverted into the new bridge deck.

Earthworks Associated with as follows:

Approximately 28 kilometres of new High Quality Dual Carriageway (to motorway standard).
Widening the Nenagh Bypass (approximately 10km) to provide a High Quality Dual Carriageway.
Approximately 2km of new single carriageway to link the proposed M7 to the existing N7 at Birdhill
Total Excavation on Project --     3,200,000 Cu m [excluding on site quarry]         
Rock Cut from Earthworks Outline -- 2,000,000 Cu m [Excavated by Blasting & Mechanical Breakers]  
Quarry Within Site Bounds --    900,000 Cu m [Used as main sourced of crushed stone on project. Incl Cl. 804, Capping Cl. 616 & Cl 503 Drainage Stone, Also used for the manufacture of chips for surfacing works and general rock fill on the project]

Unsuitable Material Disposed to Tips                 250,000 Cu m
Total Fill on Project --                                       2,850,000 Cu m
Fill Below E.O. as Dig and Replace of Bogs         400,000 Cu m
Fill Used to Construct & Maintain Haul Rds       200,000 Cu m
Net Import on Contract from External Sources   150,000 Cu m

Drainage Works Associated with as follows:

Approximately 28 kilometres of new Motorway.
Widening the Nenagh Bypass (approximately 10km) to provide a Motorway.
Approximately 2km of new single carriageway to link the proposed M7 to the existing N7 at Birdhill
Filter Drains ranging from 225 to 450mm Diameter --            54,000m
Carrier Drains ranging from 225 to 1.2m Diameter --              46,000m
Fin Drains --                                                                              35,000m
Open Drains & Ditches --                                                         40,000m

Wetland Treatment Ponds & Infiltration Basins
To Facilitate combined volume of approximately               
17 Ponds required on contract varying from full retention
Ponds to settlement ponds with liner, penstocks etc  --           65,000Cu m
Pre-Earthworks Piped Drainage Culverts ranging in
Size from 900mm to 2100mm Diameter incl Headwalls --        4,500m
Concrete Channel 1500mm wide --                                          38,000m
[formed using slipform kerber]
Median Slot Drain 225 to 300 mm --                                        14,000m
[formed using slipform kerber]
Precast Box Drainage Culverts ranging in size from 1.0m  X 1.5m units to 2.1m x 1.8m piled units -- 250m

Coffey Group, Athenry, Co. Galway, Ireland Tel: +353 91 844356 Fax: +353 91 844519 Email: info@coffeygroup.com