In offshore wind projects, marine geotechnical assessments are critical to ensure that foundations are safe, reliable, and designed to withstand marine conditions. 


SanCo´s Task


Description

Desk Study and Preliminary Data Review

Historical Data Collection

Review of Geological and Geophysical Data

Preliminary Site Assessment

Geophysical Survey Management

Seismic Profiling 

Sub-Bottom Profiling 

Side-Scan Sonar Survey 

Magnetometer Survey 

Geotechnical Site Investigation

Soil Sampling (Coring) 

Cone Penetration Testing (CPT) 

In-situ Testing 

Seabed Sampling (Grab Sampling) 

Laboratory Testing of Soil Samples

Physical Properties Testing 

Mechanical Properties Testing 

Consolidation and Compressibility Testing 

Chemical and Environmental Testing 

Data Processing and Analysis

Seismic and Soil Data Interpretation 

Geotechnical Parameter Modeling 

Stability Analysis 

Foundation Design Input and Recommendations

Load-Bearing Capacity Assessment 

Settlement and Deformation Analysis 

Scour Potential and Protection Measures 

Seismic Hazard Assessment 

Report and Documentation

Geotechnical Survey Report 

3D Soil and Bedrock Model 

Design Basis Document 

Risk and Mitigation Plan

1.


Desk Study and Preliminary Data Review


  • Historical Data Collection: Gather existing data on the site, such as bathymetric maps, geological surveys, soil borings, sediment layers, and historical geotechnical reports.
  • Review of Geological and Geophysical Data: Study previous geological reports and seismic profiles to understand regional geological features, fault lines, and sediment properties.
  • Preliminary Site Assessment: Assess site conditions based on preliminary data to determine the need for further detailed investigation.

2.


Geophysical Survey

Management

 


  • Seismic Profiling: Perform shallow and deep seismic surveys (e.g., multichannel seismic reflection) to characterize sediment layers, bedrock depth, and any geological anomalies.
  • Sub-Bottom Profiling: Use sub-bottom profilers to map sediment layers and detect variations in seabed strata that impact foundation design.
  • Side-Scan Sonar Survey: Conduct a side-scan sonar survey to create images of the seabed surface, identifying features such as boulders, sand waves, or potential obstructions.
  • Magnetometer Survey: Detect ferromagnetic objects (e.g., shipwrecks, pipelines) that may pose risks or require specific positioning of turbines.

    3.


    Foundation Design Input and Recommendations

    • Load-Bearing Capacity Assessment: Evaluate soil capacity to support turbine foundations under axial and lateral loads, considering wind, wave, and current forces.
    • Settlement and Deformation Analysis: Estimate potential settlement and tilting of foundations over time, focusing on long-term soil behavior and consolidation.
    • Scour Potential and Protection Measures: Analyze soil erodibility and predict scour around foundations; recommend protective measures like rock armoring or scour mats.
    • Seismic Hazard Assessment: Assess risks of seismic events, especially in areas prone to earthquakes, and determine foundation reinforcements needed to resist dynamic loading.
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