EN 1998-5:2024/prA1

Eurocode 8 - Design of structures for earthquake resistance - Part 5: Geotechnical aspects, foundations, retaining and underground structures

1.1   Scope of EN 1998-5
(1)   This document establishes general principles for the design and assessment of geotechnical systems in seismic regions. It gives general rules relevant to all families of geotechnical structures, to the design of foundations, retaining structures and underground structures and complements EN 1997-3 for the seismic design situation.
(2)   This document contains the basic performance requirements and compliance criteria applicable to geotechnical structures and geotechnical systems in seismic regions.
(3)   This document refers to the rules for the representation of seismic actions and the description of the seismic design situations defined in EN 1998-1-1 and provides specific definition of the seismic action applicable to geotechnical structures.
1.2   Assumptions
(1)   The assumptions of EN 1990 apply to this document.

Eurocode 8 - Auslegung von Bauwerken gegen Erdbeben - Teil 5: Geotechnische Aspekte, Gründungen, Stütz- und Untertagebauwerke

Eurocode 8 - Calcul des structures pour leur résistance au séisme - Partie 5 : Aspects géotechniques, fondations, soutènements et structures souterraines

Evrokod 8 - Projektiranje potresnoodpornih konstrukcij - 5. del: Geotehnični vidiki, temelji, oporne in podzemne konstrukcije

1.1 Področje uporabe EN 1998-5
(1) Ta dokument določa splošna načela za projektiranje in ocenjevanje geotehničnih sistemov v potresnih območjih. Nudi splošna pravila, ki so pomembna za vse vrste geotehničnih konstrukcij, za projektiranje temeljev, podpornih konstrukcij in podzemnih konstrukcij ter dopolnjuje EN 1997-3 za potresne projektne situacije.
(2) Ta dokument vsebuje osnovne zahteve glede zmogljivosti in merila skladnosti, ki se uporabljajo za geotehnične konstrukcije in geotehnične sisteme v potresnih območjih.
(3) Ta dokument se nanaša na pravila za predstavitev potresnih vplivov in opis potresnih projektnih situacij, opredeljenih v EN 1998-1-1, ter zagotavlja specifično definicijo potresnega vpliva, ki se uporablja za geotehnične konstrukcije.
1.2 Predpostavke
(1) Predpostavke iz EN 1990 veljajo za ta dokument.

General Information

• Status: Not Published
• Publication Date: 01-Aug-2027
• ICS: 91.010.30 - Technical aspects
• ICS: 91.120.25 - Seismic and vibration protection
• Technical Committee: CEN/TC 250 - Structural Eurocodes
• Drafting Committee: CEN/TC 250/SC 8/WG 7 - Evolution of Eurocode 8
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 26-Mar-2026
• Due Date: 02-Mar-2026
• Completion Date: 26-Mar-2026
• Ref Project: SIST EN 1998-5:2024/oprA1:2026 - Eurocode 8 - Design of structures for earthquake resistance - Part 5: Geotechnical aspects, foundations, retaining and underground structures

Relations

• Amends: EN 1998-5:2024 - Eurocode 8 - Design of structures for earthquake resistance - Part 5: Geotechnical aspects, foundations, retaining and underground structures
• Effective Date: 30-Jul-2025

Overview

EN 1998-5:2024/prA1 is a draft amendment to Eurocode 8, focusing on the design of structures for earthquake resistance, specifically addressing geotechnical aspects, foundations, retaining structures, and underground structures. Developed by CEN/TC 250, this standard introduces updated principles and compliance criteria for geotechnical systems in seismic regions. It complements EN 1997-3 and works in conjunction with other relevant Eurocodes for a harmonized approach to seismic design in the built environment.

The document encompasses rules and recommendations for the seismic design situation, representation of seismic actions, and detailed modifications to technical clauses that deal with site response, soil-structure interaction, foundations, retaining systems, and underground facilities.

Key Topics

• General Principles for Seismic Geotechnical Design: The standard sets out overarching rules applicable to various types of geotechnical structures in seismic areas, ensuring safety and resilience.
• Seismic Action Representation: Refers to the seismic actions and design situations as described in EN 1998-1-1, tailoring these for geotechnical applications.
• Performance Requirements and Compliance: Establishes the basic performance criteria for geotechnical systems under seismic loading.
• Technical Revisions: The amendment contains updates such as:
  • Revised definitions and terms related to soil and foundation properties
  • Clarified rules for seismic action and ground properties
  • Enhanced guidance for soil-structure interaction, including damping calculation methods
  • Updated formulae for foundation stiffness and radiation damping of pile foundations
  • Modifications to procedures for liquefaction analysis and simplified tunnel design
• National Adaptability: Recognizes and allows for adjustments at national levels through National Annexes to accommodate specific regulatory or geological contexts.

Applications

The guidance in EN 1998-5:2024/prA1 is practical for a range of building and civil engineering projects in seismic regions:

• Foundations: Ensures that shallow and deep foundations are designed to withstand seismic forces, considering stiffness, damping, and interaction with the structure above.
• Retaining Structures: Provides the grounding for designing retaining walls and other structures that must resist earthquake-induced earth pressures.
• Underground Structures: Lays out considerations for tunnels, basements, and other subsurface works, targeting the unique challenges of seismic loads below ground.
• Soil-Structure Interaction Modelling: Offers methodologies for evaluating how the interaction between soil and structure affects seismic performance, optimizing design and improving resilience.
• Site Response Analysis: Guides the evaluation of how ground conditions affect seismic wave propagation and structure response.

Adhering to this standard supports safer, more reliable infrastructure, reduces earthquake risks, and meets regulatory demands for seismic design.

Related Standards

EN 1998-5:2024/prA1 integrates with and complements several other key European standards in seismic and geotechnical engineering:

• EN 1998-1-1: General rules, seismic actions, and rules for buildings
• EN 1997-3: Geotechnical design, specific rules for the seismic situation
• EN 1997-1, EN 1997-2: Geotechnical investigation and testing
• EN 1998-2: Bridges in seismic regions
• EN 1998-3: Assessment and retrofitting of buildings for earthquake resistance
• EN 1990 and EN 1990-1: Basis of structural design

By following these harmonized standards, professionals can ensure compliant, robust designs that address the full scope of seismic geotechnical requirements across Europe.

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Keywords: Eurocode 8, EN 1998-5, earthquake resistance, seismic design, geotechnical structures, foundations, retaining walls, underground structures, soil-structure interaction, site response, liquefaction, CEN, seismic engineering standard, structural safety.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2026
Evrokod 8 - Projektiranje potresnoodpornih konstrukcij - 5. del: Geotehnični vidiki,
temelji, oporne in podzemne konstrukcije
Eurocode 8 - Design of structures for earthquake resistance - Part 5: Geotechnical
aspects, foundations, retaining and underground structures
Eurocode 8 - Auslegung von Bauwerken gegen Erdbeben - Teil 5: Geotechnische
Aspekte, Gründungen, Stütz- und Untertagebauwerke
Eurocode 8 - Calcul des structures pour leur résistance au séisme - Partie 5 : Aspects
géotechniques, fondations, soutènements et structures souterraines
Ta slovenski standard je istoveten z: EN 1998-5:2024/prA1
ICS:
91.010.30 Tehnični vidiki Technical aspects
91.120.25 Zaščita pred potresi in Seismic and vibration
vibracijami protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
EN 1998-5:2024
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
March 2026
ICS 91.010.30; 91.120.25
English Version
Eurocode 8 - Design of structures for earthquake
resistance - Part 5: Geotechnical aspects, foundations,
retaining and underground structures
Eurocode 8 - Calcul des structures pour leur résistance Eurocode 8 - Auslegung von Bauwerken gegen
au séisme - Partie 5 : Aspects géotechniques, Erdbeben - Teil 5: Geotechnische Aspekte,
fondations, soutènements et structures souterraines Gründungen, Stütz- und Untertagebauwerke
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 250.

This draft amendment A1, if approved, will modify the European Standard EN 1998-5:2024. If this draft becomes an amendment,
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of
this amendment into the relevant national standard without any alteration.

This draft amendment was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1998-5:2024/prA1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Modifications throughout the whole document . 4
2 Modification to Clause 3, “Terms, definitions and symbols” . 4
3 Modification to Clause 4, “Basis of design” . 4
4 Modification to Clause 5, “Seismic action” . 4
5 Modification to Clause 6, “Ground properties” . 4
6 Modification to Clause 7, “Evaluation of the seismic response of the construction site”
..................................................................................................................................................................... 5
7 Modification to Clause 8, “Soil-structure interaction” . 5
8 Modification to Clause 9, “Foundation system”. 6
9 Modification to Clause 10, “Earth retaining structures” . 6
10 Modification to Clause 11, “Underground structures” . 6
11 Modification to Annex B, “Procedure for liquefaction analyses” . 6
12 Modification to Annex D, “Impedance functions for surface and deep foundations”. 6
13 Modification to Annex H, “Simplified analytical expressions for the seismic design of
tunnels” . 9
European foreword
This document (EN 1998-5:2024/prA1:2026) has been prepared by Technical Committee CEN/TC 250
“Structural Eurocodes”, the secretariat of which is held by BSI. CEN/TC 250 is responsible for all
Structural Eurocodes and has been assigned responsibility for structural and geotechnical design matters
by CEN.
This document is an amendment to EN 1998-5:2024 and is currently submitted to the CEN Enquiry.
The following main changes to EN 1998-5:2024 are included in the amendment:
— modification of Clause 8.1 to account for radiation damping in the force-based approach, in a similar
way as in the displacement-based approach;
— addition of formulas for the variation with frequency of the real part of foundation impedances;
— specification of the domain of validity of pile stiffnesses;
— addition of radiation dashpots for pile foundations.
The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part
of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to
CEN by the European Commission and the European Free Trade Association.
The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product
and test standards, and to identify requirements for execution, materials, products and testing that are
relied upon by the Eurocodes.
The Eurocodes recognize the responsibility of each Member State and have safeguarded their right to
determine values related to regulatory safety matters at national level through the use of National
Annexes.
1 Modifications throughout the whole document
Replace “EN 1990:2023” with “EN 1990-1:2023+A1:2026”.
Replace “EN 1990” with “EN 1990-1”.
Replace “EN 1997-3:— ” with “EN 1997-3:2025”.
Replace “EN 1998-3:— ” with “EN 1998-3:2025”.
Replace “EN 1998-1-2:— ” with “EN 1998-1-2:2026”.
Replace “EN 1998-2:— ” with “EN 1998-2:2025”.
Replace “5 % damping” with “5 % damping ratio”.
2 Modification to Clause 3, “Terms, definitions and symbols”
In 3.1.24, replace “EN 1997-1:2024, 4.1.2.3” with “EN 1997-1:2024, 4.1.2.2”.
   
In 3.2.1.2, replace “ u ” with “ u ”, “ u ” with “ u ” and “ v ” with “ v ”.
rp Rp rs Rs r R
In 3.2.1.2, add the definition “l Pile active length”.
c
In 3.2.1.4, replace “α ” with “a ”, “α ” with “a ”, “α ” with “a ” and “α ” with “a ” and move these symbol
p p s s Rp Rp Rs Rs
definitions to 3.2.1.2 Lower case Latin symbols.
In 3.2.1.4, replace “Coefficient reflecting the spatial variation with depth of horizontal ground motion”
with “Coefficient reflecting the dependence on depth of the equivalent horizontal ground motion within
the ground mass under consideration” in the definition of β .
H
3 Modification to Clause 4, “Basis of design”
In 4.1(1), replace “EN 1998-1-1:2024, 4.3(1)” with “EN 1998-1-1:2024, 4.3(2)”.
In Table 4.1, 2nd and 4th rows, 3rd column, replace “A1.2” with “A.1.3”.
In 4.3(1), replace “EN 1998-1-1:2024, 4.3(1)” with “EN 1998-1-1:2024, 4.3(2)”.
In 4.3(1), NOTE 2, replace “EN 1998-1-1:2024, 4.3(1)” with “EN 1998-1-1:2024, 4.3(2)”.
In 4.3(3), replace “EN 1998-1-1:2024, 4.3(3) to (5)” with “EN 1998-1-1:2024, 4.3(4) to (6)”.
In 4.3(3), NOTE 1, replace “EN 19
...