Waterfront South Central, which is being developed by Ronan Group Real Estate (RGRE), involves the construction of 3 no. commercial office buildings and will transform Dublin’s North Docklands.

It will see the development of Citi’s new European bank headquarters. The nine-storey future home of Citi in Ireland will come complete with roof terraces overlooking the river Liffey and Dublin’s wider cityscape, an underground car park, retail, and gallery exhibition spaces.

M&N Civil Engineering Ltd were acquired to complete both the enabling works and bulk dig excavation with disposal for this development.

The bulk excavation of this project was a strategical dig operation. The dig itself was composed of 135,000m³ that had to be excavated and removed offsite. This consisted of over 58,000m³ contaminated materials across five different disposal waste categories.

The formation level dig for the basement was over 16 metres in depth and required various temporary works designs which were implemented by M&N. These included inventive stepped batters with a 6,500m² surface, which were completed parallel to both the north and east boundaries of the basement dig. The west and south of the basement were bordered by CFA piles. M&N installed a temporary propping system and assisted with the installation of ground anchor props bored through the CFA piles. A temporary ramp was also installed and conveyed in accordance with development of the basement to keep a consistency of works at all times.

The positioning of the basement development is within 25 metres of the River Liffey, with the basement dig formation 12.00m below water levels. M&N assisted with the dewatering throughout the basement excavation, constructing a settlement pond at ground level, assisting the install of all boreholes, and strategically excavating the basement in order to maximise output of the dewatering system.

M&N’s scope of works:

• Disposal of 12,000m³ existing contaminated pile arisings stockpiled on site
• Demolition of existing concrete slabs and structures including removal offsite
• Setup and installation of site compound and welfare
• Pile attendance for completion of all pile works – CFA piles, pile anchors and structural piles
• Removal of all contaminated pile arisings offsite
• Construction of an on-site settlement pond and attendance to de-watering
• Supply of temporary works designs
• Implementing TW designs on site – basement batters and ramps
• Bulk excavation including removal of 135,000m³ material offsite
• Stockpiling and assistance with testing of materials where required
• Supply and installation of 4,000m³ pile mat
• Installation of propping system including ancillary works
• Cropping and prepping of over 500 no. structural piles
• Road sweeper provided for duration of excavation works