Project Description

Project Overview

This landmark project for Cork, a redevelopment of the iconic Páirc Uí Chaoimh in the heart of a municipal park, is the first stadium in Ireland designed to current spectator safety guidelines. It is multi-functional in use and will cater for large conferences and events while maintaining and building on a proud history of spectacular matches and concerts at the stadium. State of the art LED flood lighting system, rainwater harvesting, heat recovery and building management systems ensure the energy performance is in line with the stadium’s modern facilities.

Malachy Walsh and Partners were appointed as design project manager with responsibility for managing the project from inception to completion. The firm was responsible for all engineering disciplines, fire engineering and environmental assessment. MWP also acted as Project Supervisor for the Design Process (PSDP) and Design and Assigned Certifiers.

The other project members were:

Client: Cork GAA County Board

Architect: Scott Tallon Walker

Planning: Cunnane Stratton Reynolds

Archaeologist: Lane Purcell

Quantity Surveyors: Michael Barrett Partnership

Main Contractor: John Sisk & Son (Holdings) Ltd.

The new stadium is constructed of a combination of insitu concrete (utilising GGBS for the piling and foundation works to maximise the environmental benefits) and precast concrete for its aesthetic quality and performance. The precast concrete elements included raker beams, seating tier beams and precast cladding panels. Best practice sightlines and spectator comfort are balanced with structural and dynamic requirements.

The new stadium a capacity of 45,300 persons incorporating, 21,300 seated spaces and 24,000 standing spaces. Spectators are accommodated in the new 3 spectator tier South Stand, with a capacity of 13,300 persons, the single tier area North Stand with a capacity of 8,000 persons and the refurbished, extended Terraces at the Blackrock and City end, accommodating 12,000 persons. All stands and terraces, comprising 4 sectors, are designed to be self-contained, incorporating concourses and spectator facilities.

South Stand

The South Stand comprises 4 levels of spectator concourses, premium level, conference centre, players’ areas, administration offices and plant room.  All players, officials’ facilities and associated services are provided at ground-floor level, served by a central ‘street’. This enables team buses to enter the stadium and deliveries to be made without interaction with spectators. The bowl concept of the previous stadium was retained by matching the perimeter parapet level around the single-tier section with the South Stand middle level.

The design brief for the South Stand premium level required an area of column free, unobstructed, multifunctional space to cater for conferences, dinner functions, meetings and events for up to 450 persons. Achieving this meant omitting 2 No. structural columns, thereby creating a clear span of 22.8m that had to be bridged. The solution that was adopted was a reinforced concrete vierendeel-type truss.

The roof covering the South Stand is 40m long and consists of stayed cantilever steel trusses. Counterbalance to the trussed structure is provided by the colonnade of columns at the south elevation, accommodating the compressive and tensile forces arising and transmitting these forces to the supporting reinforced concrete columns and foundations.

The subsoil conditions on the site dictated the use of bored piling and suspended ground slabs throughout. Continuous Flight Auger piles of average depth of 16-18m were used and varied in diameter from 450-900mm.

North Stand and Terraces

The North Stand and West and East Terraces were designed to link the old stadium to the new one by keeping the original bowl shape which was a key feature of the previous stadium and enhanced the atmosphere on match days. These works involved extensive demolition of the existing structures. The roof of the single tier North Stand was constructed using 21m long cantilevered castellated steel beams, supported by reinforced concrete columns along the north elevation. The spectator tiers were constructed in precast concrete in their entirety. The reinforced concrete columns also support the cantilevered floodlit masts overhead.

The existing precast concrete frames of the terraces were retained, strengthened and extended to support a new single precast concrete tier at each of the West and East Terraces. A major factor in the design of the terraces was the desire to relocate the vomitories from the existing positions to a higher level, thereby ensuring greater dispersion of spectators on entering the terraces and alleviating the problem arising from spectators entering at a relatively low level within the terrace.

Wind Modelling

MWP commissioned and oversaw a wind tunnel study to assess the wind loads relevant to the structural design of the two cantilever roofs. This involved the use of a 1:300 scale model of the proposed structures and all features in a 450m radius around the stadium. This study presented wind pressures relevant to the site and structure which achieved efficiency when compared to pressures derived from the prescriptive methods of Eurocodes. This allowed a rationalisation of the steel member sizes and hence a more sustainable use of the materials.

Mechanical and Electrical

The incoming electrical supply is 150 KVA and suffices for non-match-day event activity. When the electrical level exceeds this threshold, four generators with an overall capacity of 3.2 MW serve the stadium in event mode with auto control and management of generator load. The stadium also includes a PA/VA system, fibre data network and a high definition PTZ camera security system.

The stadium has 100% LED lighting with PIR control and a 1500 lux LED full programmable floodlight system. This is the first time that LED lighting has been provided in a stadium in Ireland and significantly reduces glare and eliminates flicker in comparison with the more frequent current use of metal halide lighting. The latter is being used in the second playing pitch with a lux level of 500. Particular care was taken in the design to ensure control of light spill levels to the adjoining roads and nearby housing.

Rainwater harvesting was a key sustainability target and the stadium has capacity for holding 54,000 litres of grey water supply for toilets and pitch sprinklers. There is a high efficiency 1.9MW modulating gas boiler system and instantaneous hot water without the need for storage. A Computational Fluid Dynamics analysis was carried out for the service road which included for ventilation with smoke simulation. Páirc Uí Chaoimh has a full Building Management System and also includes siphonic roof drainage on the South Roof (7,600m2 surface area).

External Works

As part of the overall project there was extensive redevelopment of the external areas. The north stream was diverted via a new 140m long precast concrete box culvert and the south stream was diverted and upgraded with a new open channel drain. In order to cross the streams, 2 No. HGV class bridges (14m & 18m spans) were required and these consisted of precast concrete beams with insitu abutments.

Adjacent to the stadium is Ireland’s largest fully floodlit state of the art 4G artificial pitch with which complements the stadium development and the future development of the Municipal Marina Park. Beneath the artificial playing pitch is 5300m3 of flood storage. The attenuated water is discharged from the underground holding tank to the Atlantic Pond, and ultimately through controlled conditions to the River Lee.

The external works also included reinforced concrete retaining walls and fencing, extensive hard standing and landscaping, a granite spine route through the park and parking and public walkways. A detailed study was carried out by MWP into improving the spectator use of available transport and parking at appropriately designated areas.

Building Information Modelling (BIM)

BIM was utilised on this project from the outset when initial site structural surveys were modelled in 3D using Revit. Conceptual scheme design proposals were modelled and used for client presentations throughout the design process and visualisations and photomontages were used at all stages from planning permission to the final seating colour scheme.

The 3D model facilitated efficient Architectural and Engineering design team collaboration and Navisworks was used for coordination and clash detection.

During the construction stage of the project, the 3D model was used in order to present some of the more complicated structural interfaces to the construction team and IFC models were issued to sub-contractors to aid coordination and detailing. In conjunction with this, IFC models from structural steel and precast concrete sub-contractors were incorporated back into the federated model to check for and resolve any potential issues.

Project Completion

The design commenced in January 2012 and substantial project completion was achieved in July 2017 in time for the first major games which were the All Ireland Hurling Quarter Finals. The project has received several awards and nominations as noted below:

 – Winner of Engineers Ireland Award for Best National Engineering Project 2017

– Nominated for Irish Concrete Society Award for Best Building 2018

– Nominated for Irish Construction Excellence Awards for Best Leisure/Tourism Project 2018

– South Stand Transfer Structure nominated for ACEI Award for Innovation 2018

For further details about the project please see link below to the MWP article “Legend on the Lee: The Redevelopment of Cork’s Páirc Uí Chaoimh Stadium” which was published in the Engineers Ireland Journal.