September 30, 2015

The investigation revealed that achieving even small penetrations of the footing would allow ratios of horizontal load to vertical reaction (or dead-weight of the structure) far in excess of the values identified in the available literature

Project Title

Development of a novel geotechnical framework for the optimisation of tidal turbine foundations

Location

Digby, Nova Scotia

Country

Canada

Client

OpenHydro

Business Sectors

Infrastructure

Services (Technical Disciplines)

OpenHydro is currently developing two tidal arrays in the Bay of Fundy, Canada, and in Paimpol-Brehat, France. The foundation solutions for these sites are gravity base structures supported by penetrometer footings, founded on the underlying bedrock strata. No design guidelines are currently available to size these footings.

In order to optimize the design of these structures OpenHydro and GDG undertook an experimental programme aimed at developing a novel design approach. Load testing of 1/3 scale foundations was undertaken to investigate the footing behaviour at an onshore test site with similar geological conditions to the offshore deployment site

Project Objectives/Outcomes

The investigation revealed that achieving even small penetrations of the footing would allow ratios of horizontal load to vertical reaction (or dead-weight of the structure) far in excess of the values identified in the available literature.

The successful delivery of the geotechnical analysis and testing programme has allowed significant design efficiency to be achieved by OpenHydro with significant impact to both capital outlay and the levelised cost of energy.

Our Role

GDG is the geotechnical consultants responsible for

1. development of hypothesis for the design framework,
2. the design of the test programme,
3. sourcing an onshore test site,
4. undertaking load test programme,
5. interpretation of the results

Geoscience Ireland Contact

Kenneth Gavin – kgavin@gdgeo.com