Large scale field tests

Large scale onshore field tests were carried out in two locations to test the response of monopiles to lateral loading in sands and clays, which are representative of typical North Sea soils. A range of scale foundations were tested, including piles of 2.0m diameter, in the spring of 2015. The response of the monopile foundations and surrounding soil was measured under both monotonic and cyclic loading.

A summary of the testing methods and geometries can be found in the ECSMGE conference paper 'Field testing of large diameter piles under lateral loading for offshore wind applications'. 

For further information contact Dr Byron Byrne (OU), (OU) or  (UCD).

Some images from the manufacturing and testing process are provided below.

Steel rolling

On the 26th of June the PISA project partners were invited to NLMK Dansteel A/S' facilities north of Copenhagen to witness the rolling and testing of the PISA steel. Below are some pictures from the rolling of the steel plates.


Steel rolling

Steel rolling 2

 

Pile manufacturing

The steel plates from NLMK Dansteel A/S have reached Bladt Industries' production yard in Northern Jutland where Bladt Industries will begin to manufacture the PISA project testing piles. 

Pile material in Bladt yard 1

 

Pile material in Bladt yard 2

 

Piezometer installation

On the 29th of September, push in piezometers were installed on the site to measure the build up and dissipation of pore pressures during pile driving and the accumulation of pore pressure during the monotonic and cyclic tests.

In-situ CPT truck

 

Piezometer installation

 

Piles arrive on site

On the 2nd of October the first piles arrived on site in Cowden.

Mid-size piles on truck

 

Mid-size crane lift

 

Large pile unload

Installation completed

On the 9th of December the final piles were installed By Dawson Construction Plant in Cowden, following a successful campaign in Dunkirk.

Cherry picker view of Cowden installed piles

Testing completed

The successful testing campaigns at the sand site in Dunkirk and the clay site in Cowden concluded on the 21st July. This campaign featured tests on piles of 0.273m, 0.762m and 2.0m diameter, with varied length and thickness as well as monotonic and cyclic loading, featuring above and below ground instrumentation to measure displacements and loads.

0.273m diameter pile test

0.762m diameter pile test

Instruments on mid-size pile test

2.0m diameter pile test