EN 1993-4-1:2007/A1:2015

SLOVENSKI STANDARD
01-november-2014
Evrokod 3: Projektiranje jeklenih konstrukcij - 4-1. del: Silosi
Eurocode 3 - Design of steel structures - Part 4-1: Silos
Eurocode 3 - Bemessung und Konstruktion von Stahlbauten - Teil 4-1: Silos
Eurocode 3 - Calcul des structures en acier - Partie 4-1: Silos
Ta slovenski standard je istoveten z: EN 1993-4-1:2007/FprA1
ICS:
65.040.20 3RVORSMDLQQDSUDYH]D Buildings and installations for
SUHGHODYRLQVNODGLãþHQMH processing and storage of
NPHWLMVNLKSULGHONRY agricultural produce
91.010.30 7HKQLþQLYLGLNL Technical aspects
91.080.10 Kovinske konstrukcije Metal structures
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
FINAL DRAFT
EN 1993-4-1:2007
NORME EUROPÉENNE
EUROPÄISCHE NORM
FprA1
August 2014
ICS 65.040.20; 91.010.30; 91.080.10
English Version
Eurocode 3 - Design of steel structures - Part 4-1: Silos
Eurocode 3 - Calcul des structures en acier - Partie 4-1: Eurocode 3 - Bemessung und Konstruktion von Stahlbauten
Silos - Teil 4-1: Silos
This draft amendment is submitted to CEN members for unique acceptance procedure. It has been drawn up by the Technical Committee
CEN/TC 250.
This draft amendment A1, if approved, will modify the European Standard EN 1993-4-1:2007. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey 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: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1993-4-1:2007/FprA1:2014 E
worldwide for CEN national Members.

EN 1993-4-1:2007/FprA1:2014 (E)
Contents Page
Foreword .3
1 Modification to the Foreword .4
2 Modifications to 1.2, Normative references .4
3 Modification to 1.6.1, Roman upper case letters .4
4 Modification to 1.6.2, Roman lower case letters .4
5 Modification to 2.7, Modelling of the silo for determining action effects .4
6 Modification to 2.9.1, General .4
7 Modification to 2.9.2.2,Partial factors for resistances .4
8 Modification to 2.10, Durability .5
9 Modification to 4.2.2.1, General .5
10 Modification to 4.2.2.3, Consequence Class 2 .5
11 Modifications to 4.4, Equivalent orthotropic properties of corrugated sheeting .6
12 Modifications to 5.3.2.4, Buckling under axial compression .8
13 Modification to 5.3.2.5, Buckling under external pressure, internal partial vacuum and
wind .9
14 Modification to 5.3.2.6, Membrane shear . 10
15 Modifications to 5.3.3.3, Buckling under axial compression . 10
16 Modifications to 5.3.4.1, General . 12
17 Modifications to 5.3.4.2,Plastic limit state . 12
18 Modification to 5.3.4.3.1, General . 13
19 Modifications to 5.3.4.3.3, Stiffened wall treated as an orthotropic shell . 13
20 Modifications to 5.3.4.3.4, Stiffened wall treated as carrying axial compression only in the
stiffeners . 14
21 Modification to 6.3.1,General . 18
22 Modifications to 6.3.2.5, Local flexure at the transition . 19
23 Modification to 6.3.2.7, Buckling in hoppers . 19
24 Modification to 6.4.1,Supporting structures . 20
25 Modification to 8.2.2,Uniformly supported transition junctions . 20
26 Modification to 8.3.4.3,Annular plate transition junction . 22
27 Modification to 8.5.3, Base ring . 22
28 Modification to 9.4.1,General . 22
29 Modification to 9.4.2, General bending from direct action of the stored material . 23
30 Modification to 9.5.1, Forces in internal ties due to solids pressure on them . 23

EN 1993-4-1:2007/FprA1:2014 (E)
Foreword
This document (EN 1993-4-1:2007/FprA1:2014) has been prepared by Technical Committee CEN/TC 250
“Structural Eurocodes”, the secretariat of which is held by BSI.
This document is currently submitted to the Unique Acceptance Procedure.
EN 1993-4-1:2007/FprA1:2014 (E)
1 Modification to the Foreword
In the Section "National Annex for EN1993-4-1", replace the following entry:
"
− 6.3.2.7 (3)"
with:
"
− 6.3.2.7 (4)".
2 Modifications to 1.2, Normative references
In the entry dedicated to EN 1990, replace "EN 1990" with "EN 1990:2002".
In the entry dedicated to EN 1993, in the list, replace "Part 1.6:" with "Part 1.6:2007:".
3 Modification to 1.6.1, Roman upper case letters
Replace:
"R local radius at the crest or trough of a corrugation."
φ
with:
"r local radius at the crest or trough of a corrugation.".
φ
4 Modification to 1.6.2, Roman lower case letters
Replace:
" wavelength of a corrugation in corrugated sheeting;"
with:
"l wavelength of a corrugation in corrugated sheeting;".
5 Modification to 2.7, Modelling of the silo for determining action effects
Replace Paragraph (1)P with:
"(1)P The general requirements set out in EN 1990 shall be followed.".
6 Modification to 2.9.1, General
Replace Paragraph (1)P with:
"(1)P The general requirements set out in EN 1990 shall be satisfied.".
7 Modification to 2.9.2.2,Partial factors for resistances
Add two new Paragraphs (4) and (5) after Paragraph (3)P:
EN 1993-4-1:2007/FprA1:2014 (E)
"(4) Where hot rolled steel sections are used as part of a silo structure, the relevant partial factors for
resistance should be taken from EN 1993-1-1.
(5) Where cold-formed steel sections are used as part of a silo structure, the relevant partial factors for
resistance should be taken from EN 1993-1-3.".
8 Modification to 2.10, Durability
Replace Paragraph (1) with:
"(1) The general requirements set out in 2.4 of EN 1990:2002 should be followed.".
9 Modification to 4.2.2.1, General
After Paragraph (2), add the following new Paragraphs (3) to (5):
"(3) Where the silo is subject to any form of unsymmetrical bulk solids loading (patch loads, eccentric
discharge, unsymmetrical filling etc.), the structural model should be designed to capture the membrane shear
transmission within the silo wall and between the wall and rings.
NOTE: The shear transmission between parts of the wall and rings has special importance in construction using bolts
or other discrete connectors (e.g. between the wall and hopper, between the cylinder wall and vertical stiffeners or
support, and between different strakes of the cylinder).
(4) Where a ring girder is used to redistribute silo wall forces into discrete supports, and where bolts or
discrete connectors are used to join the structural elements, the shear transmission between the parts of the
ring due to shell bending and ring girder bending phenomena should be determined.
(5) The stiffness of the stored bulk solid in resisting wall deformations or in increasing the buckling resistance
of the shell structure should only be considered where a rational analysis is used and there is clear evidence
that the solid against the wall is not in motion at the specified location during discharge. In such situations, the
relevant information on the flow pattern, the pressure in the solid and the properties of the specific stored bulk
solid should be determined from EN 1991-4.
(6) Where a corrugated silo exhibits mass flow, the solid held stationary within the corrugations should not be
considered as stationary in (5).".
10 Modification to 4.2.2.3, Consequence Class 2
Delete the following Paragraphs (10) to (12):
"(10) Where the silo is subject to any form of unsymmetrical bulk solids loading (patch loads, eccentric
discharge, unsymmetrical filling etc.), the structural model should be designed to capture the membrane shear
transmission within the silo wall and between the wall and rings.
NOTE: The shear transmission between parts of the wall and rings has special importance in construction
using bolts or other discrete connectors (e.g. between the wall and hopper, between different strakes of the
barrel).
(11) Where a ring girder is used to redistribute silo wall forces into discrete supports, and where bolts or
discrete connectors are used to join the structural elements, the shear transmission between the parts of the
ring due to shell bending and ring girder bending phenomena should be determined.
EN 1993-4-1:2007/FprA1:2014 (E)
(12) Except where a rational analysis is used and there is clear evidence that the solid against the wall is not in
motion during discharge, the stiffness of the bulk solid in resisting wall deformations or in increasing the
buckling resistance of the structure should not be considered.".
11 Modifications to 4.4, Equivalent orthotropic properties of corrugated sheeting
Replace the notation lines in Paragraph (3) with:
"where:
d is the crest to crest dimension;
l is the wavelength of the corrugation;
r is the local radius at the crest or trough.".
φ
Replace Figure 4.2 with:
"
Key
1 effective middle surface
Figure 4.2 — Corrugation profile and geometric parameters
".
Replace Paragraph (4):
"(4) All properties may be treated as one-dimensional, giving no Poisson effects between different directions."
with:
"(4) The equivalent properties of the sheeting in each of the two principal directions may be treated as
independent, so that strains in one direction do not produce stresses in the orthogonal direction (no Poisson
effects).".
Replace Paragraph (5) with the following paragraph and renumber accordingly all the following equations in
the subclause:
"(5) The equivalent membrane properties (stretching stiffnesses) may be taken as:
C = Et (4.2)
x x
C = Et (4.3)
y y
C = Gt (4.4)
xy xy
where:
EN 1993-4-1:2007/FprA1:2014 (E)
t is the equivalent thickness for the smeared membrane stiffness normal to the corrugations,
x
given by:
2t
t = (4.5)
x
3d
t is the equivalent thickness for the smeared membrane stiffness parallel to the
y
corrugations, given by:
2 2
 
π d
 
t = t 1+ (4.6)
y
 
4l
 
t is the equivalent thickness for the smeared membrane shear stiffness, given by:
xy
t
t = (4.7)".
xy
2 2
 
π d
 
1+
 
 4l 
Replace Paragraph (6) with:
"(6) The equivalent bending properties (flexural stiffnesses) are defined in terms of the flexural rigidity for
moments causing bending stresses in that direction, and may be taken as:
D = EI (4.8)
x x
D = EI (4.9)
y y
D = GI (4.10)
xy xy
where:
I is the equivalent second moment of area
...