Ocean Wind is New Jersey's first utility-scale offshore wind farm.
The wind farm will consist of nearly 150 turbines and will be constructed approximately 15 miles off the coast of southern New Jersey. Ocean Wind is scheduled to be operational in 2024 and ultimately will supply 1,100 megawatts (MW) to more than 500,000 homes. The objective of this phase of the project was to investigate offshore soils at selected locations for the inter-array cable and three separate export cable routes. The investigation included ball and piezocone Cone Penetration Testing (CPT), Thermal Resistivity Testing, vibrocore sampling, and borehole sampling.
Geosyntec's Scope of Services
Geosyntec was retained to process the CPT data, perform soil classification and laboratory testing on the vibrocore and borehole samples, compile the onshore and offshore geotechnical laboratory data into files for each cable installation that was consistent with the Association of Geotechnical and Geoenvironmental Specialists format and the ultimate client's additional specifications (i.e., AGS4+ format), and prepare factual reports for each cable installation that presented the measured and derived geotechnical parameters, geotechnical profiles, and a detailed summary of CPT processing and results.
Onshore geotechnical laboratory testing included classification and photos, density, specific gravity, maximum density, minimum density, particle size (sieve and hydrometer), Atterberg limits, thermal conductivity, electrical resistivity, unconsolidated undrained (UU) compression tests, pH, organic content, sulfate content, chloride content, carbonate content, handheld torvane, and pocket penetrometer. There were nearly 1,300 samples and approximately 3,500 onshore laboratory tests performed. Offshore geotechnical laboratory testing included moisture content, pH, thermal conductivity, handheld torvane, and pocket penetrometer. Additionally, there were over 250 CPTs performed offshore.
The CPTs were performed for the inter-array cable and the three export cable routes over multiple months by two different contractors. Geosyntec processed the data, clarified data gaps, resolved inconsistencies between test methods by the two contractors, and presented the results in a uniform format. The vibrocore and borehole samples were also collected over multiple deployments. Geosyntec organized and tracked nearly 1,300 samples and over 4,000 onshore and offshore test results, coordinated data management and evaluation by cable route, and prepared three separate reports simultaneously (two export cable routes were combined into a single report at the ultimate client's request). Geosyntec also provided guidance in resolving differences between estimated properties from the CPT investigation and laboratory test results. Geosyntec worked directly with our client and the ultimate client to ensure the data file, CPT results, and reports met the clients' needs.
- Location: Offshore New Jersey
- Client: Alpine Ocean Seismic Survey
- Project Practice Areas: Geotechnical
- Type of Facility: Offshore Wind Farm
- Services Provided: Geotechnical laboratory testing, Cone penetration test processing, Generation of AGS-compliant data file, Factual reporting of results
- Type of Work: Penetration Test Processing, and Reporting
- Governing Regulation: Federal