As part of the enabling works for the Thames Tideway Tunnel Project, temporary cofferdams comprised of anchored twin sheet pile wall systems needed to be constructed. The significant tide level variations along the River Thames presented challenges in terms of the lateral stress on the cofferdam structures. A-squared supported detailed design and needed versatile geotechnical software to simulate the behavior of both the soil and the structures to achieve an efficient design.

They selected PLAXIS to design the cofferdams using a combination of plane strain analysis and 3D soil structure interaction, enabling performance assessment of the structures under serviceability conditions and the evaluation of the ultimate limit of forces for the pile sheet walls and ties. Using Bentley’s application to perform numerical modeling and automate scripts enabled them to improve design efficiency, resulting in value engineered and sustainable design solutions that reduced the carbon footprint compared to traditional design approaches.