Horizon has a range of shallow seabed sampling techniques which complement both our geophysical survey and geotechnical investigations. These systems can be used in water depths ranging from very shallow to 1000s of metres deep.
Grab samples such as the Van Veen, Hamon or Day grab are traditionally used for ‘ground truthing’ and can offer a cost effective and quick solution to sample analysis. Where the superficial sediments are of interest, these grabs can recover sediment within the top 1m of the seabed. This is particularly useful when characterising large scale seabed reflectance areas for LiDAR or environmental studies.
Where larger sediment samples are required, Horizon can perform box coring. These are deployed in a similar manner as the grab sampling and can be utilised for seabed classification and surface soils analysis.
Where seabed sampling is required to penetrate deeper into the seabed Horizon can perform drop cores / vibro cores or piston cores. These typically penetrate up to 10m dependent upon seabed conditions and are particularly useful for pipeline or cable route surveys. The sediment samples recovered are disturbed cores and can be analysed in the laboratory for strength and identification. They are also extremely effective for dredging analysis and sand searches.
Our range of seabed CPTs include the Roson 40KN. This captures numerical data from the surface sediments of the seabed which are utilised for stratigraphy analysis and strength calculations. Seabed CPTs are most effective when combined with a coring method to allow the numerical data and physical samples to be integrated into a single integration.
In response to our client’s requirements, we have designed, built and commissioned a 200kN seabed CPT system utilising industry leading CPT software and hardware. The system can be operated from a variety of DP1 and DP2 vessels and is typically utilised for deep push CPTs. The system can penetrate to 40m dependent upon seabed conditions and is ideally suited to site characterisation studies or engineering for foundation design.