Offshore Renewable Energy
Connect seabed, subsurface and environmental evidence to support site selection, foundation design, cable routing and installation planning.
Critical Decision Risks
- Highly variable soil stratigraphy and glaciomarine boulder fields
- Subsea geohazards, buried paleo-channels and UXO magnetic anomalies
- Monopile refusal, cyclic p-y soil degradation and cable burial depth-of-lowering uncertainty
Evidence Outcomes
- Integrated 3D high-resolution seismic and deep CPTu ground-model synthesis
- Traceable geotechnical parameter derivation for monopile, jacket, and floating anchor design
- Optimised inter-array and export cable burial risk assessments (CBRA)
1. The Decision Problem
Offshore wind turbines have expanded into massive $15\text{–}20\text{ MW}$ class machines requiring pile penetrations exceeding $50\text{–}80\text{ m}$ in water depths from shallow continental shelves ($15\text{–}60\text{ m}$) to deep floating waters ($100\text{–}1,000\text{ m}$).
The engineering decision problem is non-trivial: developers must de-risk foundation sizing against cyclic lateral loading (millions of wave and wind cycles) and avoid catastrophic pile refusal or cable exposure due to seabed sandwave migration.
Offshore Wind Foundation Ground Model
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MetOcean Forcing [ 100-yr Extreme Wave (Hs: 14.8m) + 15MW Wind Turbine ]
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Seabed (0m) [ Sandwave Dynamics & Scour Protection Zone ]
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0m to -30m [ Holocene Soft Marine Clay & Dense Sand Layers (CPTu) ]
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-30m to -70m [ Overconsolidated Glacial Till & Hard Chalk Formation ]
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Foundation Base [ Monopile Tip Penetration / Suction Anchor Embedment ]2. Integrated Evidence Strategy
Step 1: Geophysical Reconnaissance & Hazard Scoping
- Ultra-High-Resolution (UHR) 3D Seismic: Mapping shallow acoustic blanking, paleo-valleys, fault escarpments, and gas chimneys with sub-meter vertical resolution.
- Side-Scan Sonar & Magnetometer Arrays: Multi-channel magnetic gradient surveys for UXO (unexploded ordnance) clearing and boulder cluster delineation.
Step 2: In-Situ Geotechnical Testing & Soil Mechanics
- Seabed CPTu (Cone Penetration Testing with Pore Pressure): Continuous tip resistance ($q_c$), sleeve friction ($f_s$), and pore pressure dissipation ($u_2$) logging down to $-60\text{ m}$.
- Advanced Laboratory Testing: Resonant column, cyclic simple shear (DSS), and triaxial tests to derive cyclic stiffness degradation curves ($p\text{-}y$ curves and $t\text{-}z$ springs) for turbine natural frequency matching.
Step 3: Cable Route Assessment (CBRA) & Seabed Mobility
- Sub-Bottom Profiler & Acoustic Doppler Current Profilers (ADCP): Quantifying dynamic bedform migration rates to calculate required depth-of-lowering (DoL) for inter-array and HVDC export corridors.
3. Decision-Ready Engineering Deliverables
| Deliverable | Key Engineering Outputs | Primary Stakeholder |
|---|---|---|
| Integrated 3D Ground Model | Continuous 3D soil volume with spatial shear strength ($\pm 5\text{ kPa}$) | EPCI Foundation Engineers |
| UXO Clearance Dossier | ALARP (As Low As Reasonably Practicable) magnetic anomaly sign-off | Marine Warranty Surveyors (MWS) |
| Cable Burial Risk Assessment | Trenching feasibility indices, boulder risk matrix, DoL profile | Cable Installation Contractors |
Floating Offshore Wind Foundation & Cyclic Soil Mechanics
Connect site characterization directly to anchor and mooring decisions under repeated cyclic loading.
This is a forming collaboration proposal. Capability needs and workstreams are exploratory until partner commitments are explicitly confirmed.
Start with the decision you need to make
Share the project stage, unresolved uncertainty and existing evidence. OceanHub uses that context to frame the next evidence and capability discussion.