Post on 12-Apr-2020
EBC/EEA - Offshore Wind Energy Seminar SeriesSession 2 - Logistics: Garnering Wind Power Offshore
Foundation Design Options
Presented by: Scott Key, AMEC Paragon, Houston, Texas (November 2007)
Onshore Wind Farm Development
� Foundations:
� Spread footings (bearing)
� Piled foundations
� Materials:
� Reinforced concrete
� Construction:
� Typical onshore
construction techniques
Offshore Wind Farm Development
� Offshore Foundation Concepts:
� Steel mono-pile (caissons)
� Gravity based structures
� Open frame steel structure(jacket and piles)
� Floating structures
Steel Mono-Pile (Caisson)
� Shallow water (<30')
� Very dependent on
geotechnical data
� Large diameter
� Pile driving equipment
� Penetration below mudline ≃ 150'
� Dynamics
� No structural redundancy
Gravity Based Structure
� Concrete box (normally concrete, but may be steel)
� Float into position; ballast into place
� Prepared sea bottom; uniform bearing
� Shallow water (30' to 40')
� May require piles
� Dynamics
� No structural redundancy
Jacket and Piles
� Open frame steel structure
� Main or skirt piles
� Water depth (probably <150';
economic decisions; shallow
to very deep)
� Dynamics (much more rigidity)
� Structural redundancy (multiple
piles; redundant framing)
� Normally no mud-line
preparation
Jacket and Piles (continued)
Jacket and Piles (continued)
Floating Structures
� Spread mooring
� Piles for mooring system
� Deeper water
� Dynamics
� Redundant mooring and buoyancy
Foundation Options
� Steel Mono-pile (Caisson)
� Gravity Based Structure (GBS)
� Jacket and Piles
� Floating
Foundation Rankings
344444Floating
111222Jacket
321133GBS
111211Mono-pile
ConstructabilityStormRisk
Distance from shore
MaintenanceInstallation
CostFabrication
CostOPTIONS
ASSESSMENT CATEGORIES