Consulting & Engineering ⁄
Geotechnical & Geophysical Consulting
Our team consists of multidisciplinary geotechnical engineers who have many years of experience within the offshore industry and possess both excellent design and analytical skills combined with direct experience of working offshore. Our staff are specialists in site characterisation strategies, offshore site investigation (both geophysical and geotechnical), offshore site investigations, geotechnical design, installation analysis and jack-up leg penetration analyses for offshore oil and gas and wind turbine foundations.
Ground Modelling & Geotechnical Interpretation
We integrate geo-data, interpretation and analysis to capture ground conditions that may impact engineering projects. We build early stage ground models by performing regional geological assessments and desk studies using publicly available data. We iteratively update the ground model to incorporate factual and interpretive geo-data, which include morphological (terrain), geophysical (subsurface) and geotechnical (soil) datasets. We perform geohazard assessments and drilling/shallow hazard assessments and represent the results within 4D ground models.
Our team have developed ground models for the world’s largest and most complicated offshore wind farm sites. We utilise advanced software to manage and interpret large data sets of ground investigation results to:
- Identify engineering units across a site
- Understand expected ground behaviour
- Develop geotechnical design parameters
- Identify and manage ground-based risks
- Assess lateral and vertical ground variability
We also work closely with geophysicists to produce a ground model benefiting from the advantages of both geotechnical and geophysical surveys.
Our teams apply statistical and analytical models to spatially quantify the interaction of infrastructure with the ground. We use GIS to perform site-wide foundation screening and we perform spatial and zonal clustering assessments to group areas of a site with common properties. We perform GIS-based slope stability screening for geohazard assessment, sediment transport modelling, least cost routing analysis for pipeline/cable route optimisation and 3D volume difference calculations for excavation / fill applications.
Our geotechnical engineers have designed over 500 offshore wind farm foundations, and are experienced at:
- Offshore foundation design
- Finite Element Modelling
- Seismic and liquefaction assessment
We have designed monopiles, jacket piles, gravity bases, mat foundations, ground anchors and suction caissons. We use the latest standards, industry research and best practice to ensure that our designs are safe, efficient, reliable and satisfy latest code and certification requirements.
Our team utilises a life-cycle approach to identify possible design issues early in the ground model process and mitigate the risks through improved site investigation methods and design studies.
Foundation Installation Analysis
Following foundation design our geotechnical engineers often undertake the installation analysis and management, this includes:
- Pile driveability assessments
- Site supervision during foundation installation
- Pile driving induced fatigue analysis
- Seabed preparation advice
- Mudmat design
Cable Route Analysis and Planning
We have wide-ranging experience in the design and management of cable routes to ensure the effective protection of the cable system throughout its design life. We have our own in-house cable experts and consultants who work closely with our in-house geotechnical team. The team can review the available information such as SI, bathymetry, seabed mobility and other hazards to prepare burial risk assessments and assess the expected performance of available installation tools.
Jack-Up Leg Penetration Analyses
We are experienced in jack-up drilling rig leg penetration analyses and have developed bespoke software to predict spudcan penetrations using the latest relevant codes and standards. The calculation assesses the spudcan capacity considering layered soils and identifies risks such as rapid leg penetration and punch through.
Based on the penetration prediction, we either undertake leg extraction analysis or scour studies to further understand relevant risks. We have undertaken over a thousand analyses for soils worldwide.
We have access to and use a large and increasing database of previous loading and penetrations to constantly optimise our analyses.
The penetrations, fixities and V-H envelopes determined by the geotechnical team are then used by our structural engineering team in their Site-specific Assessments.
The offshore wind industry is expanding geographically into emerging markets in seismic prone areas. Consideration on seismic activities and their impact are essential for the engineering design and construction for WTGs and their foundations. As an ABL company, OWC have global experience and in-depth knowledge in the seismic condition studies to incorporate earthquake impacts in offshore engineering design and construction. Our staff have the technical expertise and commercial track record in delivering site-specific probabilistic seismic hazard analyses (PSHA), seismic acceleration time history development, site-specific ground response analyses and soil-structure interaction analyses.
Quantitative Risk Assessment
We assess geo-risks in context with project risks, bringing together expert judgement and analytical modelling. We map seabed features and provide spatial analysis of geohazard constraints. We analyse the stability of slopes, perform liquefaction analysis and fault displacement hazard assessments. We use hazard and risk registers to qualitatively assess risk and analyse geohazard probability and equipment vulnerability to quantitatively assess risk. We identify risk mitigation and perform gap analyses to assess the value of additional information.
Geospatial Data Management
We build geographical information systems for data management and spatial analysis. We perform GIS database curation specific to a project’s requirements involving data digitising and integration, spatial data processing, metadata handling and dataset versioning. GIS database delivery is via a desktop or web-GIS solution.