Embedded retaining wall design using numerical methods according to second-generation Eurocode 7

Abstract

Originally published in the 1990s, the Eurocodes are currently being updated to form the second generation of technical standards. A significant addition to the new Eurocode is the theoretical procedure for verifying ultimate limit states using numerical methods, presented in the new Eurocode 7 Part 1, Clause 8.2, “Procedure for numerical models”. Unlike in the current Eurocode 7, an explicit procedure for verifying ultimate limit states using numerical methods is presented here for the first time.

This thesis examines how the second generation of Eurocodes may affect the calculations related to the design of anchored sheet pile walls in Finland. The thesis reviews the new verification cases and partial factors as outlined in EN 1997:2024, and Chapter 3 offers a practical procedure for applying numerical methods in design.

As part of adopting the new Eurocode numerical procedure, the Input Factoring is intended to be adopted for the limit state verifications of embedded retaining walls in Finland. Currently, only the Output Factoring is used for structural ultimate limit state verifications.

Chapter 4 of this thesis examines the performance of embedded retaining walls under limit state conditions. The example calculations evaluate the structural reaction forces and safety of the walls. This aids in understanding how the introduction of EN 1997-1:2024 affects the performance of retaining walls.

The research suggests that the new procedures may significantly affect the calcu-lation results in certain situations, leading to support structures that must withstand higher design loads. The differences between factoring approaches, as well as calculations done with Plaxis and GeoCalc software, were sometimes considerable.

The results of the thesis can be used as additional material for decision-making related to the upcoming Finnish National Annex. At the time of writing, the nationally determined parameters used in the thesis were not officially confirmed.