Project outline 

Located in Dublin City Centre, the site formed part of the Trinity College campus. To meet the expanding need for student accommodation, the Oisín House project was commissioned by Trinity College Dublin and awarded to Bennett Construction.  

Murphy were chosen as the works contractor for the rotary bored piling for the scheme. With a double basement to be constructed at the new building, our previous track record of delivering excellence in restricted city centre piling jobs stood in our favour. 

“Logistically this was a very challenging site but our team on the ground managed to keep all three rigs working safely and efficiently.” - Chris Fox, Murphy International Ltd. 

Key challenges 

With the main entrance at a one way bus corridor on Pearse Street, there were restrictions to site access, plant movement and deliveries. There was also no parking available on site. These and other challenges meant that achieving project completion within a strict time frame and on budget would require all of Murphy’s specialist resources. To mitigate congestion, staff used adjacent carparks and we encouraged the use of the ‘cycle to work’ scheme. Effective communication and involvement with key stakeholders on site overcame the risks of intensive plant and operative movements, in such a densely populated environment. This also made sure there was no increase in city centre traffic congestion as a result of our works. 

There were challenges involved in completing rotary bored piles in such a tight, prohibitive working area with high volumes of site traffic. This was tackled by assembling a highly experienced and motivated team of operatives and management. We kept the client aware of the lack of space available to us and the risks it posed to the team. The client in turn facilitated us on the site. Meanwhile, we ensured our team were well equipped to deal with the challenging conditions and deliver the project successfully. 

Project delivery and innovations 

We were responsible for all of the piling work for the project and installed the secant pile wall. This was formed by contiguous secant piles which acted as a retaining wall and provided water cut off for the proposed double basement. This allowed subcontractor, Lloyd Acoustics, to mobilise and carry out the rock anchor installations. Installing rock anchors on three sides, instead of a pile cap and internal bracing, was a Murphy design innovation. This proved to be invaluable to the client, in terms of cost saving and reducing the need for internal bracing. Due to Dublin City Council guidelines, only glass fibre reinforced polymer (GFRP) anchors could be used on the Pearse Street side. The remaining anchors around the site were standard steel anchors. 

We were in regular communication with the client, as constant updates on progress allowed them to ensure that ground was always available for us to pile. Likewise, advance communication with our suppliers, Kilsaran Concrete and Fairyhouse Steel, ensured deliveries were timed correctly. This prevented disruption to either the piling or main contractor works. 

This difficult project was delivered on time and budget, in very restrictive working conditions and to the client’s satisfaction. The safety, health, environmental, sustainability and quality systems implemented by Murphy for the project, received high praise from the client’s representatives. 

Key facts 
  • Secant pile wall of one hundred and ninety two 1,200mm diameter piles 
  • Pile lengths between 10 and 21m 
  • Rock sockets between 0.5 and 9m 
  • Fourteen GFRP rock anchors installed along Pearse Street 
  • Twenty four DYWIDAG steel anchors installed along remaining boundaries 
  • Rock anchor installation and testing 
  • Three rigs on site at peak: Bauer MBG24, BG26 & BG28 

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Building from the ground up

The Ground Engineering team at Murphy offers in-house pile design, value engineering and bespoke technical solutions throughout the UK and Ireland. We have a proven track record of successfully delivering both minor and major works across a range of sectors.

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