SIST EN 1997-3:2025/oprA1:2026

Eurocode 7 - Geotechnical design - Part 3: Geotechnical structures

1.1   Scope of FprEN 1997-3
(1)   This document provides specific rules to be applied in the design and verification of geotechnical structures.
1.2   Assumptions
(1)   This document is intended to be used in conjunction with EN 1990, which establishes principles and requirements for the safety, serviceability, robustness, and durability of structures, including geotechnical structures, and other construction works.
NOTE   Additional or amended provisions can be necessary for assessment of existing structures, see prEN 1990-2.
(2)   This document is intended to be used in conjunction with EN 1997-1, which provides general rules for the design and verification of geotechnical structures.
(3)   This document is intended to be used in conjunction with EN 1997-2, which gives provisions for determining ground properties from ground investigations.
(4)   This document is intended to be used in conjunction with the other Eurocodes for the design of geotechnical structures, including temporary geotechnical structures.

Eurocode 7 - Entwurf, Berechnung und Bemessung in der Geotechnik - Teil 3: Geotechnische Bauwerke

Eurocode 7 - Calcul géotechnique - Partie 3 : Constructions géotechniques

Evrokod 7 - Geotehnično projektiranje - 3. del: Geotehnične konstrukcije

1.1 Področje uporabe FprEN 1997-3
(1) Ta dokument določa posebna pravila, ki se uporabljajo pri projektiranju in preverjanju geotehničnih konstrukcij.
1.2 Predpostavke
(1) Ta dokument je namenjen uporabi v povezavi z EN 1990, ki določa načela in zahteve za varnost, uporabnost, robustnost in trajnost konstrukcij, vključno z geotehničnimi konstrukcijami in drugimi gradbenimi deli.
OPOMBA Dodatne ali spremenjene določbe so lahko potrebne za ocenjevanje obstoječih konstrukcij, glej prEN 1990-2.
(2) Ta dokument je namenjen uporabi v povezavi z EN 1997-1, ki zagotavlja splošna pravila za projektiranje in preverjanje geotehničnih konstrukcij.
(3) Ta dokument je namenjen uporabi v povezavi z EN 1997-2, ki daje določbe za določanje lastnosti tal iz raziskav tal.
(4) Ta dokument je namenjen uporabi v povezavi z drugimi evrokodi za projektiranje geotehničnih konstrukcij, vključno z začasnimi geotehničnimi konstrukcijami.

General Information

• Status: Not Published
• Public Enquiry End Date: 29-Jul-2026
• ICS: 91.010.30 - Technical aspects
• ICS: 93.020 - Earthworks. Excavations. Foundation construction. Underground works
• Technical Committee: KON - Structures
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 17-Jun-2026
• Due Date: 04-Nov-2026
• Ref Project: EN 1997-3:2025/prA1 - Eurocode 7 - Geotechnical design - Part 3: Geotechnical structures

Overview

SIST EN 1997-3:2025/oprA1:2026, developed by CEN as part of the Eurocode 7 series, sets out specific rules and requirements for the design and verification of geotechnical structures. This standard amendment is essential for ensuring the safety, serviceability, robustness, and longevity of geotechnical works such as foundations, slopes, retaining structures, embankments, anchors, and ground improvement systems. EN 1997-3 is intended for use together with EN 1990 (Basis of structural and geotechnical design), EN 1997-1 (General geotechnical design rules), and EN 1997-2 (Ground investigation and testing).

This draft amendment aligns EN 1997-3:2025 closely with the second generation of Eurocodes, integrating updates to terminology, definitions, and references for enhanced clarity, consistency, and alignment with evolving industry practices.

Key Topics

• Scope and Application: SIST EN 1997-3:2025/oprA1:2026 applies to new and existing geotechnical structures, including buildings, infrastructure, and earthworks, in conjunction with other Eurocodes.
• Terminology and Symbol Updates: The amendment revises and clarifies terms, definitions, and notations associated with geotechnical engineering, enhancing consistency across standards.
• Design and Verification Procedures: Provides detailed rules for the assessment of geotechnical structures, with explicit modifications addressing slopes, foundations, retaining walls, anchors, soil reinforcement, and ground improvement techniques.
• Reference Integration: Aligns with new and revised Eurocodes (e.g., EN 1990-1:2023+A1:2026, EN 1997-1:2024+A1:2026, EN 1997-2:2024+A1:2026), ensuring harmonized application and regulatory compliance.
• Annex Modifications: Includes focused updates to technical annexes on spread and piled foundations, retaining structures, reinforced fill, soil nailing, ground improvement, and groundwater control.

Applications

The updated SIST EN 1997-3:2025/oprA1:2026 standard is highly relevant for:

• Civil and Structural Engineers designing, analyzing, or supervising the construction of geotechnical structures in building, transportation, and infrastructure projects.
• Geotechnical Consultants performing ground investigations and providing design recommendations for earthworks, excavations, slopes, and underground works.
• Regulators and Inspectors enforcing compliance with harmonized European design codes for geotechnical safety and performance.
• Construction Contractors implementing works requiring robust geotechnical verification and adherence to Eurocode requirements.
• Academic Institutions teaching up-to-date geotechnical design methodologies in line with the latest European standards.
• Asset Owners/Managers overseeing the maintenance, assessment, or upgrading of existing geotechnical structures.

EN 1997-3 supports safe and reliable geotechnical design across diverse applications such as:

• Foundation construction for buildings and bridges
• Earthworks and embankments for highways and railways
• Retaining and support systems for excavations and slopes
• Ground improvement for challenging soil conditions
• Water control measures in flood protection and underground works

Related Standards

• EN 1990: Basis of structural and geotechnical design - Establishes general safety, serviceability, and durability principles.
• EN 1997-1: General rules for geotechnical design - Outlines fundamental design and verification for geotechnical structures.
• EN 1997-2: Ground investigation and testing - Specifies methods for determining soil and rock properties.
• EN 12715: Grouting - Requirements for grouting methods in ground improvement.
• EN 1992-EN 1996: Structural Eurocodes for concrete, steel, composite, timber, and masonry structures, referenced as needed for geotechnical works.
• prEN 1990-2: Assessment of existing structures - Provides guidance for evaluating existing geotechnical structures.

By referencing these standards, SIST EN 1997-3:2025/oprA1:2026 ensures consistency, interoperability, and best practices in geotechnical design throughout Europe.

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For engineers, designers, and construction professionals, adopting the updated EN 1997-3 supports effective geotechnical risk management, optimization of earthworks, and compliance with the latest European requirements for structural safety and durability.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2026
Evrokod 7 - Geotehnično projektiranje - 3. del: Geotehnične konstrukcije
Eurocode 7 - Geotechnical design - Part 3: Geotechnical structures
Eurocode 7 - Entwurf, Berechnung und Bemessung in der Geotechnik - Teil 3:
Geotechnische Bauwerke
Eurocode 7 - Calcul géotechnique - Partie 3 : Constructions géotechniques
Ta slovenski standard je istoveten z: EN 1997-3:2025/prA1
ICS:
91.010.30 Tehnični vidiki Technical aspects
93.020 Zemeljska dela. Izkopavanja. Earthworks. Excavations.
Gradnja temeljev. Dela pod Foundation construction.
zemljo Underground works
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
EN 1997-3:2025
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
June 2026
ICS 91.010.30
English Version
Eurocode 7 - Geotechnical design - Part 3: Geotechnical
structures
Eurocode 7 - Calcul géotechnique - Partie 3 : Eurocode 7 - Entwurf, Berechnung und Bemessung in
Constructions géotechniques der Geotechnik - Teil 3: Geotechnische Bauwerke
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 1997-3:2025. 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 1997-3:2025/prA1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Modifications throughout the whole document . 4
2 Modifications to the Introduction . 4
3 Modifications to Clause 2, “Normative references” . 4
4 Modification to Clause 3, “Terms and definitions” . 4
5 Modification to Clause 4, “Slopes, cuttings, and embankments” . 9
6 Modifications to Clause 5, “Spread foundations”. 9
7 Modifications to Clause 6, “Piled foundations” . 9
8 Modifications to Clause 7, “Retaining structures” . 11
9 Modifications to Clause 8, “Anchors” . 12
10 Modifications to Clause 9, “Reinforced fill structures” . 12
11 Modifications to Clause 10, “Soil nailed structures” . 12
12 Modifications to Clause 11, “Rock bolts and rock surface support” . 13
13 Modifications to Clause 12, “Ground improvement” . 13
14 Modification to Clause 13, “Ground water control measures” . 14
15 Modifications to Annex B, “Spread foundation” . 14
16 Modifications to Annex C, “Piled foundation” . 14
17 Modifications to Annex D, “Retaining structures” . 16
18 Modifications to Annex F, “Reinforced fill structures” . 17
19 Modification to Annex G, “Soil nailed structures” . 17
20 Modification to Annex I, “Ground improvement” . 17
21 Modification to Annex J, “Ground water control measures” . 17

European foreword
This document (EN 1997-3:2025/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 currently submitted to the CEN Enquiry.
This document will amend EN 1997-3:2025.
NOTE Some modifications are purely editorial corrections to improve the quality of the document and these will
not be tagged in the consolidated publication, as noted after the modification.
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” except in subclauses 0.1 and 3.1.
Replace “EN 1997-1:2024” with “EN 1997-1:2024+A1:2026” .
Replace “EN 1997-2:2024” with “EN 1997-2:2024+A1:2026” .
2 Modifications to the Introduction
In 0.1, after list item ‘EN 1999, Eurocode 9’, add:
“— EN 19100 Eurocode 10 — Design of glass structures”.
Replace “— New parts are under development, e.g. Eurocode for design of structural glass”
with:
“— New parts are under development, e.g. Eurocode for design of fibre-polymer composite structures
and design of tensioned membrane structures”.
3 Modifications to Clause 2, “Normative references”
Replace the reference to “EN 1990:2023” with:
“EN 1990-1:2023+A1:2026, Eurocode — Basis of structural and geotechnical design — Part 1: New
structures”.
Add the following reference:
“EN 1990-2, Eurocode — Basis of structural and geotechnical design — Part 2: Assessment of existing
structures”.
4 Modification to Clause 3, “Terms and definitions”
In 3.1, introductory paragraph, replace “EN 1990” with “EN 1990 (all parts)” and add a reference to
“EN 1997-2” to read:
“For the purposes of this document, the terms and definitions given in EN 1990 (all parts), EN 1997-1,
EN 1997-2 and the following apply.”.
Delete the definition 3.1.1.6 secondary compression.
In 3.1.1.10 reinforcing element, at the end of the definition, replace “slopes or retaining structures” with
“ geotechnical structures” to read “ …ground or engineered fill for stabilising geotechnical structures.”.
In 3.1.1.13 facing element, replace “precast panel” with “structural facing element” to read read
“modular structural facing element embedding the connections….”.
Delete the definition 3.1.6.8 tendon bond length.
Delete the definition 3.1.6.9 tendon free length.
In 3.1.7.2 basal reinforcement to embankments, delete “networks” and add “grid of” to read ”….fills
founded on grid of inclusions, or for….”.

Under preparation. Current stage: EN 1997-1:2024/prA1:2026.
Under preparation. Current stage: EN 1997-2:2024/prA1:2026.
In 3.1.9.2 rock surface support, delete the Note 1 to entry: “Rock surface support is non-structural and
includes wire mesh and sprayed concrete”.
In 3.1.10.6 diffused ground improvement, delete the “be” to read “ground improvement where the
ground improvement zone is modelled with a single set of parameters”.
Delete the definition 3.1.10.7 structural connection.
Delete the definition 3.1.10.8 contact.
Following the above deletions, update the remaining term numbers in 3.1 accordingly.

In 3.2.1:
Delete symbol and definition “A ”
Replace symbol and definition A with: “A is the net reduced cross-sectional area of the reinforcing
0,con s,con
element, allowing for the effects of potential corrosion, at the termination or connection”.
Delete symbol and definition “A' ”
gs,d
Delete symbol and definition “A ”
r,con
Revise symbol A to read “A the reduced gross cross-sectional area of the reinforcing element at the
r r
weakest section, allowing for the effects of potential corrosion.”
Revise symbol A to read “A plan area of the foundation base not including any area where there is no
red red
positive contact pressure between the foundation and the underlying ground as a result of load
eccentricity, ground shrinkage, or any other cause”.
Delete symbol and definition “A ”
ru
Delete symbol and definition “A ”
ry
Delete symbol and definition “A' ”
sn,d
Delete symbol and definition “B ”
gi
Revise symbol B to read “B equivalent diameter of an inclusion”.
ri ri
Delete symbol and definition “C”
Delete symbol and definition “C ”
a
Delete symbol and definition “C ”
p
Delete symbol and definition “D ”
ds
Add symbol and definition “D void diameter at ground surface”.
s
Revise symbol E to read “E design value of the maximum anchor force, including the lock-off load,
d.SLS d.SLS
and sufficient to prevent the serviceability limit state of the anchored structure”.
Revise symbol (EI) to read “(EI) design value of bending (flexural) stiffness of the pile, according to the
d d
structural Eurocodes”.
Delete symbol and definition “EI” one of the entries
Delete symbol and definition “E ”
ur
Delete symbol and definition “E ”
i
Delete symbol and definition “F ”
cd,SLS
Revise symbol F to read “F design value of an action to prevent a at the serviceability limit state”.
d,SLS d,SLS
Revise symbol F to read “F design value of the action that the supporting element shall provide to
d,ULS d,ULS
prevent an ultimate limit state of the supported structure or the value of design action at the ultimate
limit state for piles”.
Revise symbol F to read “F value of design action applied to the pile group or piled raft”.
group,d group,d
Delete symbol and definition “F ”
tot,k
Revise symbol H to read “H height of the material over the geosynthetic layer”.
Delete symbol and definition “H ”
s
Delete symbol and definition “H ”
v
Delete symbol and definition “I”
Delete symbol and definition “K ”
u
Delete symbol and definition “K ”
y
Delete symbol and definition “L ”
int
Delete symbol and definition “L ”
j
Delete symbol and definition “L ”
n
Revise symbol L to read “L length of the anchoring part”.
b b
Revise symbol L to read “L length of the reinforcing element beyond the failure surface (or line of
po po
maximum tension) where pull-out resistance is mobilized”.
Delete symbol and definition “L ”
ps
Delete symbol and definition “N ”
a
Delete symbol and definition “N' ”
d
Delete symbol and definition “N ”
p
Delete symbol and definition “N ”
γu
Delete symbol and definition “P ”
o
Revise symbol R to read “R measured value of an anchor’s geotechnical resistance complying
am,αULS am,αULS
with the ultimate limit state criterion α ”.
ULS
Revise symbol R to read “R ultimate compressive resistance….”.
block block
Revise symbol R replace “columns” with “inclusion” to read “R ….net area between the inclusion mobilized
g g
at a settlement…”.
Revise symbol R delete “or pile raft” to read “R design resistance of pile group”.
group,d group,d
Revise symbol R delete “vertical” add “compressive” to read “R representative ultimate
group,rep group,rep
compressive resistance of pile group”.
Delete symbol and definition “R ”
gs,int,d
to read “R ultimate compressive resistance….” .
Revise symbol Ri i
Delete symbol and definition “R ”
k,com
Delete symbol and definition “R ”
k,ds
Delete symbol and definition “R ”
m,sn,pul
Delete symbol and definition “R ” one of the entries
t,el,rep
Revise symbol R delete “drained” in the definition to read “R bearing resistance normal to the base of a
N N
spread foundation”.
Delete symbol and definition “R ”
pd
Revise symbol R delete “rigid” in definition to read “R representative value of the total resistance
sys,rep sys,rep
of the ground improvement system with inclusions”.
Delete symbol and definition “R ”
sn,int,d
Delete symbol and definition “R ”
sn,int,d
Delete symbol and definition “S ”
t
Delete symbol and definition “Sv”
Revise symbol T to read “T design service life of the structure in years”.

Delete symbol and definition “T ”
f,j
Delete symbol and definition “T ”
gs,k
Delete symbol and definition “T ”
k,cr
Delete symbol and definition “T ”
p,j
Delete symbol and definition “T ”
s,j
Delete symbol and definition “T ”
ven
Delete symbol and definition “V ”
norm
Delete symbol and definition “W ”
s
Delete symbol and definition “Ws”
Delete symbol and definition “W ”
T
Delete symbol and definition “a ”
d
Delete symbol and definition “a ”
nom
Delete symbol and definition “b”
Delete symbol and definition “b ”
gs
Delete symbol and definition “b ”
st
Delete symbol and definition “c ”
min,dur
Revise symbol d to read “d reference horizontal spacing between the test profiles for the Model Pile
ref ref
Method”.
Delete symbol and definition “e ”
d
Delete symbol and definition “e ”
j
Delete symbol and definition “f ”
md
Delete symbol and definition “f ”
yk
Delete symbol and definition “k {P}”
n
Delete symbol and definition “k ”
sn
Revise symbol k to read “k coefficient of modified subgrade reaction”.
subgrade subgrade
”
Delete symbol and definition “ktanϕ
Delete symbol and definition “m ”
y
Revise symbol n delete “pile” in definition to read “n number and type of site-specific loads tests”.
test test
Delete symbol and definition “p ”
Delete symbol and definition “p' ”
Delete symbol and definition “p ”
ps
Delete symbol and definition “p ”
sn
Revise symbol q to read “q unit shaft resistance in the i-th geotechnical unit”
si si
Delete symbol and definition “q ”
sk
Delete symbol and definition “q ”
u,field
Revise definition for symbol “q ” definition “q characteristic value of the unconfined compressive
u,imp,k u,imp,k
strength of the Class II ground improvement material;”.
Add symbol and definition “q representative value of the unconfined compressive strength of the Class
u,imp,rep
II ground improvement material;”.
Replace “improved ground” with “the rock mass” to read “q representative value of the unconfined
u,rep
compressive strength of the rock mass”.
Delete symbol and definition “s ”
Delete symbol and definition “s ”
y
s are the grid spacings of the piles in the group”.
Add symbol and definition “sy, x
Delete “in days” to read “t time (since t )”
Delete symbol and definition “t ”
Delete symbol and definition “w ”
s
Delete “ground” to read “y transverse deflection of the pile at failure”
f
Delete symbol and definition “α ”
ds
Delete “from the edge of the foundation” to read “β inclination of the
...