Prediction and observation of scour around the temporary river works for the Thames Tideway Tunnel

Estimations of scour potential at the Thames Tideway Tunnel temporary works cofferdams were made during the design phase using the Erodibility Index approach of Annandale (1995, 2006), modified by Harris et al. (2010). Intense quarterly monitoring ongoing since 2014 designed to allow an adaptive approach to scour risk management also provides a case study, allowing the approach taken for the pre-construction scour predictions to be verified. The results show excellent agreement between predictions and observations, supporting the use of a method that can take into account soil profile variability when predicting scour on the inter- and sub- tidal foreshore.