Belfast City Quays Multi-Storey Car Park

Having previously successfully installed over 400 CFA piles for the adjacent AC Marriott Hotel as part of the City Quays Development by Belfast Harbour Commissioners, Quinn Piling were contracted to design and install foundation piles for the new City Quays Multi-Storey Car Park.

The new Multi-Storey Car Park is adjacent to the M3 Motorway, between Tomb Street and Donegall Quay, providing 907 parking spaces over 9 levels.

The works comprised the design, installation and testing of 664 no. x 450mm diameter piles to depths of 27m, utilising a unique hybrid permanent steel-liner method developed by Quinn Piling to overcome the notoriously challenging soft estuarine deposits locally known as ‘Belfast sleech’. In addition, due to the seaside location, the rise and ebb of the tidal waters changed the ground conditions continuously.

Piling Scope and Details

A total of 664no. 450mm diameter CFA piles were installed. Carrying loads up to 750kN, the piles were installed by three different piling rigs, including the 140 Tonne Mait rig, which is the biggest piling rig in Ireland. We also used our Liebherr rig to install some temporary sheet piles. All this shows the range of piling rigs available from Quinn Piling and how versatile the company is to carry out a wide range of techniques in variable ground conditions.

In order to deal with very compact made ground predrilling was needed to facilitate the piling.

To deal with the very soft sleech and to ensure integrity of the deep cast insitu piles deep sacrificial steel casing was used.

A combination of sacrificial and working pile static load tests were carried out with test loads up to 1,875kN.

Project Innovation

All Quinn Piling CFA rigs are fitted with the latest generation NDT piling computer systems which enable our CFA rig operators to monitor and accurately control all aspects of the pile construction process. As each pile is completed, the rig transmits the pile data to the ‘cloud’ for review and analysis by Quinn Piling engineers which enables real-time quality control. The system provides instant data on important parameters such as auger depth, auger rotations, penetration speed, rotary torque, extraction force, extraction speed, concrete pressure, concrete flow and total concrete volume pumped.