Soil mapping for NordLink land cable route

The construction of underground extra-high-voltage direct current transmission lines (HVDC lines) requires linear interventions in the ground on the land side and can lead to considerable ground damage if not carried out properly. Knowledge of the soil conditions is of great importance for the planning and execution of the civil engineering work for laying the cable.

In order to ensure the protection of the soil during the construction of the NordLink route and in preparation for the soil monitoring programme, extensive preliminary soil investigations based on the 5th edition of the Soil Mapping Guide (KA5) were therefore required. G.E.O.S. carried out these investigations on behalf of the grid operator TenneT TSO GmbH.

• Evaluation of available investigations (soil soundings, subsoil expertise, etc.) in preparation for soil mapping
• Pedological mapping of the construction corridor of the NordLink route using 428 borehole probes; mapping in 2 stages
• Evaluation and interpretation of the pedological mapping results
• Determination of the space required for the storage of the excavated soil from the cable trench
• Determination of the space required for the storage of the excavated soil for the HDD protective pipe storage
• Determination of the space required for the storage of the excavated soil from the sleeve construction pits
• Advice on pedological construction monitoring