Alexandra Dock, Hull Green Port
In June 2012, Soil Engineering were contracted to undertake ground investigations at Hull’s Alexandra Dock as part of the Humber Estuary Renewable Energy Supercluster development.
Site investigation works were completed at Alexandra Dock where applications had been made for the demolition of existing buildings and the development of a massive facility for the manufacture, assembly, storage, handling and testing of wind turbine components for the offshore power generation industry.
Soil Engineering Solution
Soil Engineering completed works both on land and overwater within the active dock area. Overwater operations were undertaken from a spudleg barge, drilling in 10m of water.
The scope of works comprised:
- Cable percussive boreholes formed overwater to up to 20m below bed level
- CPT tests undertaken from the spudleg barge to depths of 5m below bed level and via pre-bored cable percussive boreholes to 15m below ground level
- In situ plate bearing tests at surface to determine bearing capacity of existing pavements and within observation pits at up to 1m below ground level.
- Concrete cored holes to 0.5m in order to examine pavement structure following plate bearing tests
The main works were completed in less than 4 weeks utilising in house drilling plant and resources.
Soil Engineering Value
As site works neared completion ABP Humber required information from within the tidal zone of the River Humber to design the realignment of a piled wall. It was agreed that both time and money could be saved if Soil Engineering carried out the works utilising plant and equipment already on site, drawing on previous experience of drilling in tidal conditions and within a live dock environment. Adding this borehole to the scope of works negated not only procurement and additional mobilisation costs, it greatly accelerated ABP’s design programme.
The additional borehole was successfully drilled across a 5m tidal range in a single shift to a depth of 15.50m below bed level. Further additional design work was helped by adding 2 days of window sampling and dynamic probing at the end of the 4 week site period, allowing the client to advance designs for a footpath diversion.
In the decade since this investigation was completed, Alexandra Dock has been successfully transformed into a leading centre for renewable energy. Having produced over 1,500 turbine blades since opening in 2016, the 1000 employee plant is set to expand further in 2023, creating a further 200 jobs and more than doubling capacity. Soil Engineering’s ground investigation has directly contributed to green energy projects worldwide.