Second Generation of Eurocode 7 - Verification of serviceability limit states

The verification of serviceability limit states (SLS) of new geotechnical structures must be performed according to the basis of design given in EN 1990:2023 and EN 1997-1:2024. The paper explains how to determine the effects of actions specified for the serviceability limit state (SLS), based on the appropriate combination of actions and the corresponding geometrical and material properties. The effects of actions are usually expressed in terms of foundation movements. Limiting design serviceability criteria are given according to the structural sensitivity of the supported structures, using the Structural Sensitivity Classes (SSC) introduced for the first time in EN 1990:2023. The general procedure for defining limiting criteria for SLS is discussed, showing possible alternatives when there are project-specific requirements and differences in application to buildings and to bridges. The background to the design criteria for building is presented, which is broadly based on values of “allowable movement” that have appeared in the geotechnical literature over the past 70 years or so. The margin of certainty in SLS verifications is discussed. A summary of the serviceability limit states of the different geotechnical structures is given based on the specifications in EN 1997-3:2025. A distinction is made between predicting the behaviour of a structure and verifying SLS and ultimate limit states (ULS), highlighting differences in the selection of ground property values (either representative or best estimate values) used in the calculation of ground movements. Finally, the verification of SLS of existing structures according to FprEN 1990-2:2025 is also mentioned.

The paper is available for free on the website of International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) at the link below.