SIST EN 13480-6:2004/A1:2006

SLOVENSKI STANDARD
SIST EN 13480-6:2004/A1:2006
01-marec-2006
Kovinski industrijski cevovodi – 6. del: Dodatne zahteve za vkopane cevovode
Metallic industrial piping - Part 6: Additional requirements for buried piping
Metallische industrielle Rohrleitungen - Teil 6: Zusätzliche Anforderungen an
erdgedeckte Rohrleitungen
Tuyauteries industrielles métalliques - Partie 6 : Exigences complémentaires relatives
aux tuyauteries enterrées
Ta slovenski standard je istoveten z: EN 13480-6:2004/A1:2005
ICS:
77.140.75 Jeklene cevi in cevni profili Steel pipes and tubes for
za posebne namene specific use
SIST EN 13480-6:2004/A1:2006 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 13480-6:2004/A1:2006

---------------------- Page: 2 ----------------------

SIST EN 13480-6:2004/A1:2006
EUROPEAN STANDARD
EN 13480-6:2004/A1
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2005
ICS 23.040.01

English Version
Metallic industrial piping - Part 6: Additional requirements for
buried piping
Tuyauteries industrielles métalliques - Partie 6 : Exigences Metallische industrielle Rohrleitungen - Teil 6: Zusätzliche
complémentaires relatives aux tuyauteries enterrées Anforderungen an erdgedeckte Rohrleitungen
This amendment A1 modifies the European Standard EN 13480-6:2004; it was approved by CEN on 22 September 2005.
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. Up-to-date lists and bibliographical references concerning such
national standards may be obtained on application to the Central Secretariat or to any CEN member.
This amendment exists 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 Central Secretariat has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13480-6:2004/A1:2005: E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
Contents Page
Foreword .3
5 Design and calculation.4
5.2 Design.4
Annex A (normative) Calculations for buried piping.5
A.1 General.5
A.2 Materials.5
A.3 Design and calculation.5

A.3.1 Calculation procedure.5
A.3.2 Determination of the loads due to backfill .5
A.3.3 Determination of the loads due to live loads .17
A.3.4 Determination of the moments acting upon the piping .21
A.3.5 Global stability of a buried piping system .23
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 97/23/EC .28

2

---------------------- Page: 4 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
Foreword
This European Standard (EN 13480-6:2004/A1:2005) has been prepared by Technical Committee
CEN/TC 267 “Industrial piping and pipelines”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by June 2006, and conflicting national standards shall be withdrawn at
the latest by June 2006.
This European Standard has been prepared under a mandate given to CEN by the European Commission
and the European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this European
Standard.
This European Standard contains the Annex A (normative) to be added in EN 13480-6:2004, and the
Annex ZA updated to replace the current Annex ZA in EN 13480-6:2004.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
3

---------------------- Page: 5 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
5 Design and calculation
Replace title of 5.2 by:
5.2 Design
Replace 5.2.5 by:
5.2.5 Where no detailed analysis is undertaken, the maximum temperature range (including the installation
temperature) shall not exceed 35 °C, and restraining features such as buried bends and tees shall have a
separation of not less than 5 DN. Where detailed analysis is undertaken, it shall be in accordance with
EN 13480-3 supplemented by Annex A (normative).
4

---------------------- Page: 6 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
Annex A
(normative)

Calculations for buried piping
A.1 General
This annex describes the applicable requirements for buried piping, supplementing those of EN 13480-3 and
EN 13480-6.
Thus, it is proposed to deal with the calculations for buried piping taking account of the following:
 weight of the soil or backfill above the pipe according to the different types of installation;
 static and dynamic loads imposed on the ground above the pipe (e.g. traffic loads);
 flexibility and stability of the piping subjected to combined pressure and temperature change effects.
A.2 Materials
The requirements specified in EN 13480-2 apply without any restriction.
However, one shall remind that the corrosion phenomena occurring in the case of buried piping may be
significantly different from those to which piping above-ground, in ducts or tunnels are subjected.
A.3 Design and calculation
A.3.1 Calculation procedure
a) Determination of the required thicknesses from the equations given in EN 13480-3 when the piping is
subjected only to internal pressure;
b) determination of the loads due to backfill (A.3.2) and to live loads (A.3.3);
c) checking of the thicknesses defined in a) for the different operating conditions under which the loads
defined in b) are applicable (A.3.4);
d) checking of the global stability of the buried piping system.
A.3.2 Determination of the loads due to backfill
A.3.2.1 General
The installation methods for buried piping covered are as follows:
 piping in narrow trench;
 piping in wide trench or in positive projecting embankment condition.
5

---------------------- Page: 7 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
A.3.2.2 Notations
For the purposes of this annex the following notations shall apply:
C = Settlement ratio (see A.3.2.5.1 b));
tass
C Coefficient for taking into account the dynamic effect of the live loads;
=
dyn
D = External piping diameter. For standardized tubes, D is the theoretical external diameter,
o o
tolerances excluded;
e Ordered wall thickness;
ord =
E Backfill material modulus;
=
t
E Modulus of elasticity for the piping material (see EN 13480-3);
=
H Total height from the top of the piping to natural ground surface (cover);
=
t
H = Distance from the plane of equal settlement to the top of pipe;
e
k Ratio of lateral pressure to vertical pressure for the backfill material (Rankine coefficient):
=
 2
 π ϕ 
 
k = tan −
 
 
4 2
 
 
L = Width of the trench in the horizontal plane containing the top of the piping;
t
Unit weight of backfill material;
γ =
t
Angle of internal friction for the material used to fill the trench;
ϕ =
Coefficient of internal friction of backfill material;
µ =
Coefficient of sliding friction between the backfill material and the trench walls;
µ' =
 µ' is always less than or equal to µ and µ' may be taken as µ provided that backfilling material of
proper quality (homogeneity) is used;
F Load per unit length.
=
A.3.2.3 Soil properties
In the absence of specific data, the values given in the table hereafter may be used for the design and
calculation of buried piping.
6

---------------------- Page: 8 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
Table A.3.2.3 – Soil properties and backfill material
Type of soil Density ϕ ϕ µ = tan (ϕ) k µ' = tan (ϕ') µ k µ'
ϕϕ k
3
°
daN/m
a
Topsoil 1 450 22 0,404  0,184 0,184
Partially
compacted 1 440  0,330 0,500 0,165
b
(moist) topsoil
b
Saturated topsoil 1 760  0,370 0,400 0,150
c
Sandy clay  25 0,406
c
Clay  22
a
Silty clay 2 000 20 0,364  0,178 0,178
Plastic clay –
1 800 14 0,249  0,152 0,152
a
Sandy clay
a
Moist clay 2 000 12 0,213  0,139 0,139
Yellow clay, moist
and partially 1 600  0,330 0,400 0,130
b
compacted
Saturated yellow
b 2 080  0,370 0,300 0,110
clay or loam
Coarse – gravely
43
 c
sand
c
Medium sand 40
c
Fine sand 38
c
Silty sand 36
Uncompacted
1 700 31 0,601  0,192 0,192
a
sand
a
Sand - Gravel 2 000 33 0,649  0,191 0,191
a
Clayey sand 1 800 22 0,404  0,184 0,184
Saturated clayey
2 110  0,350 0,400 0,140
b
sand
b
Dry sand 1 600  0,330 0,500 0,165
b
Moist sand 1 920  0,330 0,500 0,165
c
Sludge 18
Marshy ground –
1 700 12 0,213  0,139 0,139
a
Peat
(Continued)
7

---------------------- Page: 9 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
Table A.3.2.3 (concluded)
Type of soil Density ϕ ϕ µ = tan (ϕ) k µ' = tan (ϕ') µ k µ'
ϕϕ k
3
°
daN/m
Loamy loess
(alluvial deposits) 2 100 18 0,325  0,172 0,172
a

Loam – Marl –
2 100 22 0,404  0,184 0,184
a
poor clay
a
Sandy silt 1 800 25 0,466  0,189 0,189

Gravel – Pebbles
1 900 37 0,754  0,187 0,187
a

Loose – gravelly
backfilling 1 700  0,330 0,580 0,192
b
material
Stony-sandy
backfilling 1 900  0,330 0,500 0,165
b
material
Moist-loamy
backfilling 2 000  0,330 0,450 0,150
b
material
a Calcul des sollicitations extérieures agissant sur les conduites enterrées (Calculation of external loadings acting on
buried pipings) - CERIB 1970.
b The theory of external loads on closed conduits in the light of the latest experiments - MARSTON 1930.
c Stabilité des canalisations enterrées (Stability of buried pipelines) - E.M.YASSINE et V.I. TCHERNIKINE - Moscow
1968.
A.3.2.4 Piping in narrow-trench condition
A.3.2.4.1 Definition
A piping is considered as piping in narrow-trench condition (Figures A.3.2.4.1-1 to A.3.2.4.1-4) if one of the
following conditions is satisfied:
L H
t t
< 2 and ≥ 1,5
L
D
t
0
or
L H
t t
2 ≤ ≤ 3 and ≥ 3,5
L
D
t
0
If neither of these conditions is satisfied, the piping is considered as piping in wide-trench condition.
A.3.2.4.2 Calculation of the load due to backfill
The load per unit length the piping is subjected to is given by the Equations A.3.2.4.1-1 and -2:
F = C γ L H (A.3.2.4.2-1)
1 1 t t t
8

---------------------- Page: 10 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
'
 
− 2 k µ H
 
t
 
 
L  L 
t t
 
C = 1− e (A.3.2.4.2-2)
 
1
'
2 k µ H
t  
 
The value of C may be derived directly from Figure A.3.2.4.2 as a function of the ratio H / L and of the
1 t t
product kµ'.

Figure A.3.2.4.1-1 Figure A.3.2.4.1-2

Figure A.3.2.4.1-3 Figure A.3.2.4.1-4
9

---------------------- Page: 11 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)


Figure A.3.2.4.2 – Determination of C
1
10

---------------------- Page: 12 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
A.3.2.5 Piping in wide-trench conditions or positive projecting embankment conditions
A.3.2.5.1 Definitions
a) Projection ratio.
The projection ratio, q , is defined in Figures A.3.2.5.1-1 and A.3.2.5.1-2 and the most commonly used values
r
are given in Table A.3.2.5.1-1.
Table A.3.2.5.1-1 – Values for the projection ratio q
r
q
Angle 2θθθθ
r
0° 1
30° 0,98
60° 0,93
90° 0,85
120° 0,75


Figure A.3.2.5.1-1 Figure A.3.2.5.1–2

11

---------------------- Page: 13 ----------------------

SIST EN 13480-6:2004/A1:2006
EN 13480-6:2004/A1:2005 (E)
b) settlement ratio.
The settlement ratio, C , is defined as follows:
t
...