At the time of the investigation the Eastern Docks were being utilised for vehicle import /export facilities. The area had a significant historic past use with 30% of the site area having formally comprised a dry dock, first formed over 100 years ago, which has since been in filled with an assortment of materials. Associated with this was a historic pumping station with inlet and outlet culverts, the above ground features demolished but below ground features in terms of concrete structures and foundations still present. In order to minimise cost variations once construction works were underway it was necessary to determine, with a significant degree of certainty the location of these historic structures.
In order to target these features the area was traversed on 3m centres by a specialist GPR sub contractor leading to generation of a drawing that showed locations of many of these relic structures, these were further manipulated into cross sections. Follow on work allowed for the positive identification of features through probing and slit trenches, which was demonstrated to provide a rapid and cost effective method of obtaining high quality information.
The wider investigational works involved advancing 14 boreholes across the eastern and western docks, with three within the former dry dock advanced to c.13m bgl and the remainder to 30m bgl. Challenging drilling conditions required the utilisation of multiple drill strings to assist with progress, and to ensure the integrity of the Eurocode 7 compliant samples.
Leading on from the above project OEC were commissioned to undertake some over water works, involving coring into the quay wall. Given the location of the core positions it was necessary to utilise a MEWP (Mobile Elevated Work Platform) for access to the positions. Due to the tidal nature of Southampton Water works had to be programmed around tide tides, given that some locations were below the high water mark. This coupled with the high volume of vessel movements, and rapidly changing Berth Planner led to a requirement for flexibility in coring order.
Both elements of this project was completed to the highest of standards providing excellent quality data for the ongoing design work in challenging conditions.