Arup / Doran Consulting
DAWSON-WAM were appointed by the McGinnis Group to carryout site clearance, groundworks, drainage and the installation of a secant piled basement as part of a substantial residential development at Wellington Park, Belfast.
The development consisted of 30 luxury apartments with underground basement parking for 56 cars together with the conversion of a significant detached residence into 3 luxury townhouses. The development was located in the exclusive Malone Road area of Belfast, within reach of the prestigious Queen's University.
Working within a 40m x 45m plot, DAWSON-WAM carried out the main piling works, including installation of a secant piled basement wall, excavation works and installation of concrete floor slab.
The secant wall consisted of a hard-to-hard configuration of 300nr, 630mm diameter concrete CFA piles with temporary steel casings and cage reinforcements to depths of up to 13m. The basement walls were temporarily supported by steel props and waling beams, which were removed in stages as work on the permanent concrete structure progressed. The basement consisted of a split level formation with 3 storey car parking on one side and 2 storey on the other. Bulk excavation was therefore carried out to 6m and 4m respectively.
The pile installation utilised one of DAWSON-WAM's fleet of five ABI flexible format, double auger drive rigs, which enabled boring within a few centimetres of the adjacent building and ground level carpark with minimal noise and vibration. Noise and vibration levels were continuously monitored throughout the course of the works together with deflections in the secant piled wall as the bulk excavation progressed.
The contract was completed on time within the 10 week programme period as well as to budget.