During a routine inspection of the pier substructure, severe corrosion was identified to the steel supporting piles under the pier head. EDS were awarded the contract to encase 100 piles using precast concrete encasements (provided by Stanton Bonner – Read more on their Case study here) to preserve the condition of the structure.

The approved method involved air-lifting the loose bed material around each pile and installing the split semi-circular concrete encasements with a grout bag around the base. Once in place, the grout bag was filled with a pumped micro-concrete. The precast encasing was then filled by the diver; using a proprietary high strength underwater marine grout. Due to restricted access from the pier, majority of the work was undertaken from a multicat work boat, ensuring minimal disruption to the day-to-day operations on the pier, which attracts 4 million visitors per year.

C-Tecnics video system was used throughout to allow the dive supervisor to oversee the operation, and enabled the client to check each pile encasement on completion and a various stages through the works.

In addition to the planned 100 piles, EDS undertook five emergency pile strengthening repairs which required mobilisation to site with all plant, equipment and materials within a week in order to repair five severed cast iron piles. This required close working with other contractors in order to design the repair solution and undertake the repairs as speedily as possible, allowing the pier to re-open fully in time for the busy Easter tourist season.