Case Study: Permanent Sheet Pile Basement, Albert Quay, Cork

Permanent Sheet Pile Basement, Albert Quay, Cork

Sheet Piling (UK) Ltd were employed by BAM Building Ltd for the ‘Design, Supply & Installation’ of sheet piles, associated temporary propping and permanent waterproof welding works; to form a 59.6m x 60.3m permanent double storey basement for a new prestigious commercial development on Albert Quay, Cork.

The sheet piling works facilitated construction of a double storey basement for the development which was used to provide 135No. car parking spaces and staff changing facilities.

Working closely with the Design Team including MMOS Consulting Engineers and BAM Building Ltd during the pre-construction period; Sheet Piling (UK) Ltd utilised their previous experience of undertaking similar sheet piling works in Cork to overcome the significant problems presented by the project including:-

• The double storey basement being constructed adjacent to the River Lee.
• Ground Conditions consisting of ‘Dense Gravels’ which can prove problematic for Pile Press installation.
• The works being undertaken to 2No. elevations to existing occupied residential buildings.

By adopting their previous significant experience of Giken Pile Pressing methods throughout both the UK & Ireland, Sheet Piling (UK) Ltd proposed installing the sheet piling using a sequential cased augering system which is unique to works in Cork in order to overcome the problems posed by the high tidal ground water and ground conditions.

Once the individual pile location had been successfully augered to the pile toe level, the sheet piles were installed sequential behind the auger hole using a Giken Pile Pressing method.

The unique sequential augering and pile installation method prevents problems which can otherwise occur with re-consolidation of the augered ‘Dense Gravels’ in tidal conditions.

Critically it can also prevent the risk of piles de-clutching during installation which would be extremely problematical given an excavation of 8.0m deep was required adjacent to the River Lee.

To assist driveability the leading interlock of the sheet pile was pre-applied with a hot applied bituminous sealant to reduce clutch friction during installation and also assist with de-watering during the excavation works.

Over an 8No. week installation period, a total of 399No. 13.0m long Arcelor Mittal GU27N sheet piles were successfully installed and critically upon excavation works none of the piles had de-clutched thus avoiding significant de-watering issues which would otherwise have occurred.

Once installed, a high level system of temporary steelwork propping was installed to the permanent reinforced concrete capping beam using Sheet Piling (UK) Ltd in-house welding team.

The bracing struts provided stability during excavation of the double storey basement and were removed once the basement and intermediate slabs of the basement has been constructed.

Furthermore all exposed sheet pile interlocks were welded together with a profiled steel puddle plate at the basement slab / sheet pile wall interface in order to provide a 100% watertight basement wall which form part of a Grade 2 basement as defined in BS8102:Part2:2009.

The ‘One Albert Quay’ building was designed to Gold LEED standards and once completed was recognised as the most significant new office development in Cork City Centre for many years.