Seabed and sub-seabed boulders as an engineering hazard in the marine environment; methods of detection and quantification
Seabed and sub-seabed boulders as an engineering hazard in the marine environment; methods of detection and quantification
Seabed and sub-seabed boulders are a significant design constraint, and financial risk to the design and installation of foundations for offshore Wind Turbine Generators, the trenching and installation of export and intra-array cables, and project design. Many windfarms under development in northern Europe and USA are built on geological formations which are either a direct product of, or subsequently influenced by, glaciation. These formations often contain high numbers of seabed and sub-seabed boulders; for example, the Marr Bank Formation of the North Sea. A primary objective for pre- construction geophysical surveys is to provide data to support a boulder mitigation strategy. This is required prior to installation to allow for an optimised construction methodology to be selected. The detection and quantification of boulders is the first step in a proposed five-step mitigation strategy. In this paper, we present an overview of the geophysical methods utilised for the detection of seabed and sub-seabed boulders, including the key considerations for the boulder detection requirements and subsequent survey specifications to meet these requirements. We present the technical and practical limitations to detection, as well as state-of-the-art solutions. The detection of boulders is followed by a detailed quantification of boulders, in order to understand the risks posed to engineering activities. The overall objective is to reduce engineering risk by better informing the location, design, and installation associated with emplacing infrastructure at and below the seabed.
M. J. Wetton; D. P. Vaughan; N. Dyer
18th European Conference on Soil Mechanics and Geotechnical Engineering (ECSMGE2024)
E - Environment, water and energy
Contact Information
- Secretary General - Dr A M McNamara
- Email: [email protected]
- Phone: +44 20 7040 8154
- City, University of London
- Northampton Square
- London EC1V 0HB. United Kingdom