Layered soils in the shallow subsurface (<6.0 m), North Sea: a data report

TY - BOOK

T1 - Layered soils in the shallow subsurface (<6.0 m), North Sea

T2 - a data report

AU - Johnson, Kirsten

AU - Carter, Gareth

AU - Macdonald, Caterina

AU - Coombs, William M.

AU - Bird, Robert E.

AU - Augarde, Charles

AU - Brown, Michael

AU - Sharif, Yaseen

AU - Arnhardt, R.

N1 - © UKRI 2024. All rights reserved

PY - 2024/8/1

Y1 - 2024/8/1

N2 - The Carbon Trust (2015) “Cable Burial Risk Assessment (CBRA) Methodology” document is widely used in the offshore subsea cable industry to define the cable burial Depth of Lowering (DoL). To-date, published work on anchor penetration depths has focused on single homogeneous soil units, offering limited information on the response of different soil layering combinations, and associated contrasting geotechnical properties between soil units. By interrogating >11,000 shallow cores from the entire UK North Sea area, we demonstrate that “layered” soil combinations (e.g., “sand over clay”) are statistically common across the North Sea study area. The results also highlight the importance of updating current CBRA approaches to include “layered” soils, and associated changes in geotechnical properties (e.g., strength and density) between single and layered soil units. In addition, we collated geotechnical data for input into physical and numerical modelling under-taken by the University of Dundee and Durham University respectively (see Sharif et al., 2023; Bird et al., 2023 a, b), to assess the implications for the current CBRA Methodology. Ultimately the goal is to create a new CPT-based tool for better constraining the DoL, as part of the EPSRC research grant “Offshore Cable Burial: How deep is deep enough?

AB - The Carbon Trust (2015) “Cable Burial Risk Assessment (CBRA) Methodology” document is widely used in the offshore subsea cable industry to define the cable burial Depth of Lowering (DoL). To-date, published work on anchor penetration depths has focused on single homogeneous soil units, offering limited information on the response of different soil layering combinations, and associated contrasting geotechnical properties between soil units. By interrogating >11,000 shallow cores from the entire UK North Sea area, we demonstrate that “layered” soil combinations (e.g., “sand over clay”) are statistically common across the North Sea study area. The results also highlight the importance of updating current CBRA approaches to include “layered” soils, and associated changes in geotechnical properties (e.g., strength and density) between single and layered soil units. In addition, we collated geotechnical data for input into physical and numerical modelling under-taken by the University of Dundee and Durham University respectively (see Sharif et al., 2023; Bird et al., 2023 a, b), to assess the implications for the current CBRA Methodology. Ultimately the goal is to create a new CPT-based tool for better constraining the DoL, as part of the EPSRC research grant “Offshore Cable Burial: How deep is deep enough?

KW - Soil layering

KW - UK CS

KW - Cable Burial Risk Assessment

KW - North Sea

M3 - Commissioned report

VL - OR/24/031

BT - Layered soils in the shallow subsurface (<6.0 m), North Sea

PB - British Geological Survey

CY - Nottingham

ER -