The Roadbridge / L&M Keating Joint Venture (RBLMK JV) appointed Quinn Piling for the marine drilling and piling works for the upgrade and new berthing facilities at Dublin Port, Cross Berth Quay. The works form part of the overall Alexandra basin masterplan.
Quinn Piling’s engineering department developed a novel methodology and sequence of enabling works for the construction of a combi-wall as the piles were not able to be solely installed by driving.
Quinn Piling installed 110 nr 1800mm diameter piles up to 32m deep into the Dublin Boulder Clay to form a new combi wall. Quinn Piling also installed 183nr 750mm diameter piles using CFA techniques for a concrete contiguous tie wall. Tie rods connected this wall to the front combi-wall using tie-rods.
Piling Scope and Details
The works comprised the installation and ‘mucking-out’ of 110 no. large diameter temporary pile casings (1.8m diameter) to a depth of 27m to get through the difficult Dublin boulder clay layer and enable the JV to follow closely behind to pitch and drive the 1.4m diameter permanent steel tubular piles a further 9m deeper.-Our engineering department manufactured a special pile top ‘pile-gate’ to ensure the permanent tubular piles were driven vertically and installed in the correct position with correct rotation to a lower level within the 1.8m temporary casing to ensure the sheet piles, which would be installed later by Quinn Piling, would fit perfectly between the tubes without the risk of de-clutching.
Quinn Piling mobilised its MAIT HR 420 – 800, an impressive 140 ton piling rig which is the largest in Ireland. This made light work of the large diameter piles in the Dublin boulder clay. Quinn Piling’s large diameter pile-oscillator was used to withdraw the 6m long 1.8m diameter segmental casings. This enabled the piling rig to concentrate on inserting casings and mucking-out, thereby reducing contract duration.
