37 / 2025-04-24 11:27:46

Stability of engineered reef units as scour protection around offshore foundation structures

Engineered Reef Unit Solutions (ERUSs) are increasingly used in scour protections as additional non-functional elements to comply with nature-inclusive design requirements, due to the flexibility they offer in properties and availability. A potential development step is to assess the possibility of creating entire protection layers comprising of ERUSs. To gain insights on this topic, physical model tests were conducted to obtain data on the performance of ERUS scour protection armour layers with the aim to compare them to loose rock, for which design guidelines and prediction tools are well documented. We compare the performance of ERUSs and loose rock as armour material, which shows good agreement between the behaviour of ERUS and loose rock datapoints. Observations of deformation depth at ERUS armour layers are compared with predictions of loose rock deformation depth made using a scour protection deformation model. The model shows relatively good agreement and can be used for engineering practice to provide an indication of expected deformation of ERUSs protection layers.