The uses of piling in sites having poor access or low headroom or on soft ground requires innovative solutions. Coffey has the technology, the capability, the experience and the know how to deal with these issues. The technology is the combination vibrator and hammer piling system that permits the driving of sheet piles, H piles and circular piles together with an excavator capability. Throughout Ireland, on bridges and other structures the results of this technology are evident.

Coffey Experience :

Sheet Piling

Manulla Embankment Stabilisation Works, Mayo
Client: Irish Rail
Project Value: £285,000 (ex VAT)

Project Description:

An embankment section of the Westport to Dublin line in Manulla was under distress due to the existing steep embankment 1:1. The section of track was on a long curve and stabilisation of this embankment was required. The project consisted of the installation, as permanent works, a line of sheet piles each side of the embankment to stabilise it. The works consisted of the following:

  • 199m of 11m long PU 12 sheet piles.
  • Tie-bar installation @ 5m intervals to tie each sheet pile together.
  • Trimming of all piles to the required levels.
  • Filling of granular material between existing embankment and new sheet piles.


H-Piled Foumdations

OB 411a Fanning’s – Overbridge Construction
Client: Irish Rail
Project Value: £1.2m (ex VAT)

Project Description:

The works involved the construction of an overbridge in Co. Tipperary. Piled abutments and retaining earth embankments made up the structure along with a precast deck. Due to the nature of the existing ground condition on site, the foundation for the new bridge required a series of 203x203x10 steel H piles to be driven into place to transfer the load from the bridge foundation to the rock at a depth of 15m below ground level. The steel piles were driven using a machine mounted piling rig. Load testing and untrasonic testing was carried out on all piles.



TRM - Piling (Ductile)

Greenpark Site Development Works
Client: Race Developments
Project Value: £1,200,000 (ex VAT)

Project Description:

The works involved the installation of site services to a development in Limerick City. A number of pipelines were installed including a piled pipeline 6m deep in poor ground conditions. The piles consisted of 118mm diameter ductile iron pipe piles 5.5m long with a special adapted pile cap to receive the installation hammer. These piles were installed along the route of the pipeline at 5.5m intervals and the 600mm drainage pipe was then attached to this by means of a special strap to secure the pipeline to the pile.





Aguered Piling

Clongriffin Railway Embankment Upgrade
Client: Irish Rail
Project Value: £56500,000 (ex VAT)

Project Description:

This project involved the construction of this 500m long retaining wall, which varies in height from 2m to 4m. The wall was backfilled and structural layers placed to support the new track. Ancillary works include the installation of drainage and service ducting.
Generally the design solution is to provide an L-shaped retaining wall, with the base of the wall underneath the new embankment. However, the northern 90m of the proposed retaining wall posed a problem. Irish Rail’s boundary at this location is only an average of 3m offset from the existing OHLE columns, but the embankment is approximately 3.5m high. The height of the required wall and its close proximity to the existing tracks meant that it was not practicable to install an L-shaped wall here without undermining the running rails. Therefore, Irish Rail’s designers opted for a contiguous piled retaining wall to support the embankment for this 90m stretch.

The original design was to construct 300mm diameter contiguous piles at 450mm centres to a depth of 9m below platform level (5.5m below existing ground level). To do this would have necessitated a 10m temporary widening of the embankment to support a 3m high piling platform as shown above.

This platform would have resulted in the supply, installation and removal of approximately 6000 tonnes of material. This would have necessitated approximately 1500 HGV journeys and it was desirable from an environmental as well as a cost-conscious viewpoint to develop an alternative solution.
To overcome the necessity to construct a 3.5m high piling platform as shown above, it was decided to construct the piles to ground level only and subsequently construct a 3.5m high in-situ RC wall on top of the piles, with a double sided shutter. This was explained to Irish Rail in the tender clarification meeting and they immediately saw the benefits of this and accepted the proposal.
Of equal importance was the removal of the requirement to carry out piling works at night time under possession. One of Irish Rail’s main constraints is that if any plant could fall over or slew within 2.7m of the overhead cables, then a possession and isolation is required. Due to the close proximity of the overhead cables, a standard 15 to 20m high piling rig would not have been allowed to work during the day. Therefore we consulted with various European suppliers of specialist piling plant. We decided that the excavator mounted drill was more suitable for undertaking the works, the main reason being that the drill could be attached to the jib of a Hitachi EX255 excavator. It was possible for the excavator to set up further away from the tracks while auguring.


Mini - Piling

Dromod Railway Station Upgrade
Client: Irish Rail
Project Value: £600,000 (ex VAT)

Project Description:

The project involved the extension of the railway station platform in Dromod, Co. Leitrim. The project involved the installation of mini-piles, universal column sections within the building so that the front wall could be demolished. As this was a listed structure, extreme care regarding working restrictions and health and safety issues were highly important during this project. Kentledge testing was carried out outside the building due to the space restrictions along with ultrasonic testing. There was fifty 32mm diameter mini-piles installed to a depth of 6-8m.

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