ISO 10803:2011

INTERNATIONAL ISO
STANDARD 10803
Second edition
2011-12-01

Design method for ductile iron pipes
Méthode de calcul des tuyaux en fonte ductile




Reference number
ISO 10803:2011(E)
©
ISO 2011

---------------------- Page: 1 ----------------------
ISO 10803:2011(E)

COPYRIGHT PROTECTED DOCUMENT


©  ISO 2011
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56  CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2011 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 10803:2011(E)
Contents Page
Foreword . iv
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Design procedure . 2
5  Design for internal pressure . 3
6  Design for external loads. 3
Annex A (informative) Dimensions of preferred and other class pipes . 9
Annex B (informative) Allowable depths of cover for pipes conforming to ISO 2531 . 12
Annex C (informative) Allowable depths of cover for pipes conforming to ISO 7186 . 54
Annex D (informative) Trench types . 58
Annex E (informative) Soil classification . 59
Bibliography . 60

© ISO 2011 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 10803:2011(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 10803 was prepared by Technical Committee ISO/TC 5, Ferrous metal pipes and metallic fittings,
Subcommittee SC 2, Cast iron pipes, fittings and their joints.
This second edition cancels and replaces the first edition (ISO 10803:1999), which has been technically
revised.

iv © ISO 2011 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 10803:2011(E)

Design method for ductile iron pipes
1 Scope
This International Standard specifies the design of ductile iron pipes used for conveying water, sewerage and
other fluids
 with or without internal pressure, and
 with or without earth and traffic loading.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 2531, Ductile iron pipes, fittings, accessories and their joints for water applications
ISO 7186, Ductile iron products for sewerage applications
ISO 7268, Pipe components — Definition of nominal pressure
ISO 10802, Ductile iron pipelines — Hydrostatic testing after installation
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 7268 and the following apply.
3.1
allowable operating pressure
PFA
maximum internal pressure, excluding surge, which a component can safely withstand in permanent service
3.2
allowable maximum operating pressure
PMA
maximum internal pressure, including surge, which a component can safely withstand in service
3.3
allowable site test pressure
PEA
maximum hydrostatic pressure that a newly installed component can withstand for a relatively short duration,
when either fixed above ground level or laid and backfilled underground, in order to ensure the integrity and
leaktightness of the pipeline
NOTE This test pressure is different from the system test pressure, which is related to the design pressure of the
pipeline.
© ISO 2011 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 10803:2011(E)
3.4
embedment
arrangement and type(s) of material around a buried pipeline, which contribute to its structural performance
See Figure D.1.
3.5
bedding
lower part of the embedment, composed of the lower bedding (if necessary) and the upper bedding
See Figure D.1.
3.6
bedding reaction angle
conventional angle used in the calculation model to account for the actual soil pressure distribution at pipe
invert
3.7
compaction
deliberate densification of soil during the installation process
3.8
standard Proctor density
degree of soil compaction, as defined in AASHTO T99 using a 2,5 kg rammer and a 305 mm drop
4 Design procedure
4.1 The pipe wall thickness shall provide adequate strength against the internal pressure of the fluid and
against the effects of external loads due to backfill and surcharge, i.e. traffic loadings.
Ductile iron pipes in compliance with ISO 2531 are classified according to their allowable operating pressure
for use in water applications. Ductile iron pipes in compliance with ISO 7186 are for sewerage applications
either under pressure or under gravity. Using the equations given in Clauses 5 and 6, the design of buried
pipes is performed by determining
a) the minimum pipe wall thickness for the allowable operating pressure (PFA), and
b) the depths of cover as given in Annexes B and C.
4.2 The design procedure for the pipes is the following:
a) from the allowable operating pressure of the pipeline, select the class of pipe as appropriate from
ISO 2531 or ISO 7186 [the minimum pipe wall thickness of these pipes has been calculated from
Equation (1)];
b) calculate the allowable depth of cover in accordance with Clause 6;
c) if the allowable depth of cover is not adequate, select higher a pressure class of pipe and repeat
steps 4.2 a) and b) until the allowable depth of cover is acceptable.
NOTE 1 In practice, in most cases, the pressure class and the allowable depth of cover for the pipes can be selected
from the appropriate tables in Annexes B or C without carrying out the detailed calculations as explained above.
NOTE 2 When installed and operated under the conditions for which they are designed, ductile iron pipes, fittings,
accessories and their joints maintain all their functional characteristics over their operating life, due to constant material
properties, to the stability of their cross-section and to their design with high safety factors.
NOTE 3 In certain countries, national standards or regulations can specify other design procedures.
2 © ISO 2011 – All rights reserved

---------------------- Page: 6 ----------------------
ISO 10803:2011(E)
5 Design for internal pressure
5.1 Design equation for wall thickness
The minimum wall thickness of pipes, e , shall be not less than 3 mm (as specified in ISO 2531) or 2,4 mm
min
(ISO 7186) and shall be determined using Equation (1):
PFASF DE
e  (1)
min
20R(PFA SF)
m
where
e is the minimum pipe wall thickness to resist hoop stress due to internal pressure, in millimetres;
min
1)
is the allowable operating pressure, in bar (see 5.2);
PFA
SF is the design safety factor (see 5.2);
DE is the nominal pipe external diameter, in millimetres (see Annex A);
R is the minimum ultimate tensile strength of the ductile iron, in megapascals (R  420 MPa in
m m
ISO 2531 and ISO 7186).
Nominal wall thickness, e , of the pipe is calculated as given by Equation (2):
nom
ee  1,3 0,001DN (2)
 
nom min
where DN is the nominal diameter of pipe as defined in ISO 2531 and ISO 7186, in millimetres.
Nominal pipe wall thicknesses for various classes in accordance with ISO 2531 are given in Table A.1 and
nominal pipe wall thicknesses for pressure and gravity pipe classes in accordance with ISO 7186 are given in
Table A.2.
5.2 Design safety factors
The minimum pipe wall thickness, e , shall be calculated with a design safety factor of 2,5 for the maximum
min
allowable operating pressure (i.e. PMA as indicated in ISO 2531 and ISO 7186) and a design safety factor
of 3 for the allowable operating pressure (i.e. PFA as indicated in ISO 2531 and ISO 7186).
NOTE This allows field testing of installed ductile iron pipelines in compliance with ISO 10802 by application of test
pressures up to the allowable test pressures given in ISO 2531 and ISO 7186.
6 Design for external loads
6.1 Design equation
Kq
x
 100 (3)

80SE,061
or

2
1) 100 kPa = 1 bar = 0,1 MPa; 1 MPa = 1 N/mm .
© ISO 2011 – All rights reserved 3

---------------------- Page: 7 ----------------------
ISO 10803:2011(E)

 8SE 0,061

q (3)
K 100
x
where
 is the pipe diametral deflection, in percent of external diameter, D;
K is the deflection coefficient depending on bedding reaction angle;
x
q is the vertical pressure at pipe crown due to all external loads, in megapascals;
S is the pipe diametral stiffness, in megapascals,
EI
S
3
()D
where
E is the modulus of elasticity of the pipe wall material, in megapascals (170 000 MPa for
ductile iron);
3

e
stiff
I   is the second moment of area of the pipe wall per unit length, in millimetres to the
 
12

third power;
D is the mean diameter of pipe DE e , in millimetres;
 
stiff
DE is the nominal pipe external diameter as specified in ISO 2531 and ISO 7186, in millimetres;
e is the average of the minimum pipe wall thickness of the pipe and nominal wall thickness of
stiff
pipe, in millimetres;
E is the modulus of soil reaction, in megapascals.
Pipe material stiffness values, S, may be taken from the relevant annexes of ISO 2531 and ISO 7186.
The values of E and K are given in Table 1 for each trench type and soil group.
x
NOTE The design equation is based on the Spangler model (see Figure 1), where the vertical pressure, q, is acting
downward and:
 is uniformly distributed at the pipe crown over a diameter;
 is in equilibrium with a pressure, acting upward at the pipe invert, uniformly distributed over the bedding reaction
angle 2;
 causes a pipe deflection, which gives rise to a horizontal reaction pressure at pipe sides, parabolically distributed
over an angle of 100°.
4 © ISO 2011 – All rights reserved

---------------------- Page: 8 ----------------------
ISO 10803:2011(E)

Key
1 vertical pressure, q
2 lateral reaction pressure = 0,01 E
3 vertical reaction pressure = q/sin
Figure 1 — Spangler model
6.2 Loads applied to the pipe and calculation for the allowable depth of cover
6.2.1 General
The total vertical pressure, q, acting at pipe crown is the sum of the following components:
qq q (4)
12
where
q is the pressure from earth loads;
1
q is the pressure from traffic loads;
2
NOTE The pressure from traffic loads, q , is greater than that from normal static loads applied to the ground surface;
2
however, any abnormal surface loading can require special consideration.
The value of q obtained from Equation (4) is basically a function of H (allowable depth of cover), i.e.
qf ()H (5)
Equating this to Equation (3) (see 6.1):
 (8SE 0,061 )

fH() (6)
()K (100)
x
The value of allowable depth of cover, H, may be determined after calculating the value of q as given in 6.2.2
and 6.2.3 and other parameters as defined.
© ISO 2011 – All rights reserved 5

---------------------- Page: 9 ----------------------
ISO 10803:2011(E)
6.2.2 Pressure from earth loads
Equation (7) shall be used to calculate q from the weight of the earth prism immediately above the pipe:
1
qH 0,001
1
(7)
where
q is the pressure at pipe crown, in megapascals;
1
 is the unit weight of the backfill, in kilonewtons per cubic metre;
H is the height of cover (distance from pipe crown to ground surface), in metres.
3
In the absence of other data, the unit weight of the soil is taken as being equal to 20 kN/m in order to cover
the vast majority of cases. If a preliminary geotechnical survey determines that the actual unit weight of the
3
backfill is less than 20 kN/m , the actual value may be used for determining q .
1
3
If, however, it appears that the actual value is more than 20 kN/m , the actual value should be used.
6.2.3 Pressure from traffic loads
The value of q shall be calculated using Equation (8), based on wheel load taken from national and/or local
2
applicable standards and regulations.

4
q0,04 (1 210 DN) (8)
2
H
where
q is the pressure at pipe crown, in megapascals;
2
 is a traffic load factor; the following are the given values:
 1,5: this is the general case, except access roads;
 0,75: roads where truck traffic is prohibited;
 0,50: all other cases;
H is the height of cover, in metres;
DN is the nominal size.
NOTE 1 Equation (8) is not applicable when H  0,3 m.
In the case where a national standard exists for the traffic loadings, the value of  may be given as follows:
P
 (9)
100
where P is the wheel load, in kilonewtons, for a particular type of road according to the respective national
standard.
All pipelines shall be designed for at least   0,5 and pipelines laid adjacent to roads shall be designed to
withstand the full road loading.
6 © ISO 2011 – All rights reserved

---------------------- Page: 10 ----------------------
ISO 10803:2011(E)
NOTE 2 For pipelines under railroads or airports or subjected to heavy construction traffic, special requirements can
apply according to the respective national standard and regulations.
6.3 Soil and pipe interaction
The bedding reaction angle depends on the installation conditions (bedding, sidefill compaction) and on the
pipe diametral deflection (especially for large sizes).
The modulus of soil reaction, E, of the sidefills depends on the type of soil used for the embedment and upon
the trench type (see Annex D). In the absence of applicable standards or other data, the values of E indicated
in Table 1 may be used at the design stage for five typical trench types and for six soil groups (see Annex E
for the classification of soils).
These data are valid for pipes laid under embankments as well as in trenches.
A preliminary geotechnical survey should be carried out to facilitate identification of the soil and proper
selection of E values.
E values given in Table 1 apply when trench shoring is left in place or removed in such a way as to allow
compaction of sidefill against the native trench wall; otherwise, reduced E values should be applied.
In very poor ground conditions, it may be necessary to use soil stabilization matting to prevent migration of
embedment with resultant loss of soil reaction modulus, E.
Table 1 — Modulus of soil reaction, E
Trench type 1 2 3 4 5
Very light Light Medium High
Placement of embedment Dumped
compaction compaction compaction compaction
a
Standard Proctor density of sidefill, % 75 80 85 90
Bedding reaction angle (2) 30° 45° 60° 90° 150°
K 0,108 0,105 0,102 0,096 0,085
x
E (MPa)

Soil group A 4 4 5 7 10
Soil group B 2,5 2,5 3,5 5 7
Soil group C 1 1,5 2 3 5
Soil group D 0,5 1 1,5 2,5 3,5
b b b b b
Soil group E
b b b b b
Soil group F
a
Depending on the type of soil and its moisture content, a standard Proctor density of 70 % to 80 % should normally be achieved by
simply dumping the soil in the trench.
b
Use an E value of 0 unless it can be ensured that a higher value is achieved consistently.

6.4 Allowable pipe diametral deflection
The allowable pipe diametral deflection,  , may be taken from relevant annexes of ISO 2531 and
max
ISO 7186. These values provide sufficient safety against yield bending strength of the pipe wall, lining
deformation, joint leak tightness and hydraulic capacity of the pipe. However, national standards and/or the
manufacturer's catalogues may introduce more stringent limitations, for instance 3 % for cement mortar
linings.
© ISO 2011 – All rights reserved 7

---------------------- Page: 11 ----------------------
ISO 10803:2011(E)
For each DN, the allowable pipe diametral deflection,  , is the lowest of the following:
max
a)  , which provides a safety factor of 2 against irreversible damage of the lining:
1
 for cement mortar linings (DN  DN 300):
DN 300
 3 , with a maximum of 4 %;
1
500
 for flexible linings:
  5 %;
1
b)  , which provides a safety factor of 1,5 against the yield bending strength of the ductile iron pipe wall:
2
Re DE

f nom
 100 (10)
2
SF DEe F
nom
where
R is the yield bending strength of the pipe wall material (R = 500 MPa for ductile iron);
f f
DE is the pipe external diameter as defined in ISO 2531 and ISO 7186, in millimetres;
e is the nominal pipe wall thickness, in millimetres;
nom
SF is the safety factor (= 1,5);
E is the modulus of elasticity of the pipe wall material (E 170 000 MPa for ductile iron);

DF is the deformation factor which depends mainly on the pipe diametral stiffness (for ductile iron

pipes, DF  3,5).
8 © ISO 2011 – All rights reserved

---------------------- Page: 12 ----------------------
ISO 10803:2011(E)
Annex A
(informative)

Dimensions of preferred and other class pipes
A.1 Dimensions of preferred and other class pipes for pipes conforming to ISO 2531
Dimensions of preferred and other class pipes with flexible joints classified by the allowable operating
pressure, in bar (PFA), prefixed by the letter C, i.e. C20, C25, C30, C40, C64 and C100 are given in this
annex. These are derived from Equation (1) and the data of Clause 5, and are in compliance with ISO 2531.
Table A.1 — Dimensions of preferred and other class pipes for pipes conforming to ISO 2531
Nominal iron wall thickness, e
nom
a
DE

b
DN mm
mm
C20 C25 C30 C40 C50 C64 C100

c
40 56  4,4 4,4 4,4 4,4
c
50 66  4,4 4,4 4,4 4,4
c
60 77  4,4 4,4 4,4 4,4
c
65 82  4,4 4,4 4,4 4,4
c
80 98  4,4 4,4 4,4 4,8
c
100 118  4,4 4,4 4,4 5,5

c
125 144  4,5 4,5 4,8 6,5
c
150 170  4,5 4,5 5,3 7,4
c
200 222  4,7 5,4 6,5 9,2
c
250 274  5,5 6,4 7,8 11,1
c
300 326  5,1 6,2 7,4 8,9 12,9
cd
350 378 5,1 6,3 7,1 8,4 10,2 14,8
cd
400 429 5,5 6,5 7,8 9,3 11,3 16,5
c
450 480 6,1 6,9 8,6 10,3 12,6 18,4
c
500 532 6,5 7,5 9,3 11,2 13,7 20,2
c
600 635 7,6 8,7 10,9 13,1 16,1 23,8
cd
700 738 7,3 8,8 9,9 12,4 15,0 18,5 27,5
c
800 842 8,1 9,6 11,1 14,0 16,9 21,0
c
900 945 8,9 10,6 12,3 15,5 18,8 23,4
c
1000 1 048 9,8 11,6 13,4 17,1 20,7
c
1100 1 152 10,6 12,6 14,7 18,7 22,7
c
1200 1 255 11,4 13,6 15,8 20,2
c
1400 1 462 13,1 15,7 18,2
c
1500 1 565 13,9 16,7 19,4

© ISO 2011 – All rights reserved 9

---------------------- Page: 13 ----------------------
ISO 10803:2011(E)
Table A.1 (continued)
Nominal iron wall thickness, e
nom
a
DE

b
DN mm
mm
C20 C25 C30 C40 C50 C64 C100
c
1600 1 668 14,8 17,7 20,6
c
1800 1 875 16,4 19,7 23,0
c
2000 2 082 18,1 21,8 25,4
c
2200 2 288 19,8 23,8
2400 2 495 21,4 25,8
c
2600 2 702 23,1 27,9
a
A tolerance of 1 mm applies.
b
For pipes with weld beads, see ISO 10804.
c Preferred classes.
d
For preferred classes, thicknesses are greater than the thicknesses calculated for “smoothing” between C40 and C30, and also
between C30 and C25.

A.2 Dimensions of pressure and gravity sewer pipes conforming to ISO 7186
Table A.2 — Dimensions of pressure and gravity sewer pipes conforming to ISO 7186
Nominal iron wall thickness, e
nom
a Pressure pipe: corresponding
DE
DN preferred pressure class of
mm
mm
ISO 2531
Pressure pipe Gravity pipe
80 98 4,4 3,4 C40
100 118 4,4 3,4 C40
125 144 4,5 3,4 C40
150 170 4,5 3,4 C40
200 222 4,7 3,4 C40
250 274 4,9 4,1 C30
300 326 5,1 4,8 C30
b
350 378 5,7 5,5 C30

b
400 429 6,3 C30
450 480 6,4 C25
500 532 6,5 C25
600 635 7,5 C25

b
700 738 8,5 C25
800 842 9,6 C25
900 945 10,6 C25
1000 1 048 11,6 C25
1100 1 152 12,6 C25

10 © ISO 2011 – All rights reserved

---------------------- Page: 14 ----------------------
ISO 10803:2011(E)
Table A.2 (continued)
Nominal iron wall thickness, e
nom
a Pressure pipe: corresponding
DE
DN preferred pressure class of
mm
mm
ISO 2531
Pressure pipe Gravity pipe
1200 1 255 13,6 C25
1400 1 462 15,7 C25
1500 1 565 16,7 C25
1600 1 668 17,7 C25
1800 1 875 19,7 C25
2000 2 082 21,8 C25
2200 2 288 23,8 C25
2400 2 496 25,8 C25
2600 2 702 27,9 C25
a
A tolerance of 1 mm applies.
b
For preferred classes, thicknesses are greater than the thicknesses calculated for “smoothing” between C40 and C30, and also

between C30 and C25.

© ISO 2011 – All rights reserved 11

---------------------- Page: 15 ----------------------
ISO 10803:2011(E)
Annex B
(informative)

Allowable depths of cover for pipes conforming to ISO 2531
B.1 General
Tables B.1 to B.14 show the allowable depth of cover calculated from the equations and data of Clause 6,
assuming three different values of , six soil groups and five different trench types.
NOTE The E value of 0 has been taken for soil groups E and F; this is a limit case, which can occur in soils of very
poor load-bearing capacity and/or in uncompacted, very cohesive soils.
B.2 Allowable depths of cover for pressure class pipes conforming to ISO 2531
For Tables B.1 to B.14:
a) minimum allowable depth of cover is 1 m. For depths of cover less than this, further consideration may be
necessary;
b) NR stands for “not recommended”.
Table B.1 — Allowable depths of cover for C20 pipes conforming to ISO 2531 — Cement mortar lining
Allowable depth of cover
m
DN Soil group
( = 0,5/0,75/1,5)
Type 1 trench Type 2 trench Type 3 trench Type 4 trench Type 5 trench
700
A 5,4/5,3/5,1 5,5/5,6/5,2 6,9/6,8/6,6 9,8/9,8/9,6 15,2/15,2/15,1
B 3,7/3,6/3,1 3,8/3,7/3,3 5,2/5,1/4,8 7,4/7,3/7,1 11,1/11,0/10,9
C 1,9/1,5/NR 2,6/2,4/NR 3,4/3,2/2,6 4,9/4,8/4,5 8,3/8,3/8,1
D NR 2,0/1,6/NR 2,7/2,5/NR 4,2/4,1/3,8 6,3/6,2/6,0
E/F NR NR NR NR NR
800 A 5,6/5,6/5,3 5,8/5,7/5,5 7,2/7,1/7,0 10,2/10,2/10,1 15,9/15,9/15,8
B 3,9/3,8/3,3 4,0/3,9/3,5 5,4/5,3/5,0 7,7/7,6/7,4 11,6/11,5/11,4
C 2,0/1,6/NR 2,7/2,5/NR 3,5/3,4/2,8 5,1/5,0/4,7 8,7/8,6/8,5
D NR 2,1/1,7/NR 2,8/2,7/NR 4,4/4,3/4,0 6,5/6,4/6,2
E/F NR NR NR NR NR
900 A 5,6/5,5/5,3 5,7/5,7/5,4 7,1/7,1/6,9 10,2/10,1/10,0 15,8/15,8/15,7
B 3,8/3,7/3,3 3,9/3,8/3,4 5,3/5,2/5,0 7,6/7,6/7,4 11,5/11,5/11,4
C 1,9/1,5/NR 2,7/2,5/NR 3,4/3,3/2,8 5,0/4,9/4,6 8,6/8,6/8,4
D NR 2,1/1,7/NR 2,8/2,6/NR 4,3/4,2/3,9 6,4/6,4/6,2
E/F NR NR NR NR NR

12 © ISO 2011 – All rights reserved

---------------------- Page: 16 ----------------------
ISO 10803:2011(E)
Table B.1 (continued)
Allowable depth of cover
m
DN Soil group
( = 0,5/0,75/1,5)
Type 1 trench Type 2 trench Type 3 trench Type 4 trench Type 5 trench
1000 A 5,6/5,5/5,3 5,8/5,7/5,5 7,1/7,1/6,9 10,2/10,1/10,0 15,8/15,8/15,7
B 3,8/3,7/3,3 3,9/3,8/3,5 5,3/5,2/5,0 7,6/7,6/7,4 11,5/11,5/11,4
C 1,9/1,6/NR 2,7/2,5/NR 3,4/3,3/2,8 5,0/4,9/4,7 8,6/8,6/8,4
D NR 2,0/1,7/NR 2,8/2,6/NR 4,4/4,3/3,9 6,4/6,4/6,2
E/F NR NR NR NR NR
(  0,5/0,75/1,5)
1100 A 5,5/5,5/5,2 5,7/5,6/5,4 7,1/7,1/6,9 10,1/10,1/10,0 15,8/15,8/15,7
B 3,8/3,7/3,3 3,9/3,8/3,4 5,3/5,2/5,0 7,6/7,5/7,4 11,5/11,4/11,3
C 1,9/1,5/NR 2,7/2,5/NR 3,4/3,3/2,8 5,0/4,9/4,6 8,6/8,5/8,4
D NR 2,0/1,7/NR 2,7/2,6/NR 4,3/4,2/3,9 6,4/6,3/6,1
E/F NR NR NR NR NR
1200
A 5,5/5,4/5,2 5,7/5,6/5,4 7,1/7,0/6,9 10,1/10,1/9,9 15,8/15,7/15,7
B 3,8/3,6/3,3 3,9/3,8/3,4 5,2/5,2/4,9 7,5/7,5/7,3 11,4/11,4/11,3
C 1,9/1,5/NR 2,6/2,4/NR 3,4/3,2/2,8 4,9/4,9/4,6 8,5/8,5/8,3
D NR 1,9/1,6/NR 2,7/2,6/NR 4,3/4,2/3,9 6,3/6,3/6,1
E/F NR NR NR NR NR
1400 A 5,5/5,4/5,2 5,7/5,6/5,4 7,1/7,0/6,8 10,1/10,0/9,9 15,7/15,7/15,6
B 3,7/3,6/3,3 3,9/3,8/3,4 5,2/5,2/4,9 7,5/7,5/7,3 11,4/11,4/11,3
C 1,9/1,5/NR 2,6/2,5/NR 3,4/3,2/2,8 4,9/4,8/4,6 8,5/8,5/8,3
D NR 1,9/1,7/NR 2,7/2,6/1,7 4,3/4,2/3,9 6,3/6,3/6,1
E/F NR NR NR NR NR
1500 A 5,5/5,4/5,2 5,7/5,6/5,4 7,0/7,0/6,8 10,1/10,0/9,9 15,7/15,7/15,6
B 3,7/3,6/3,3 3,8/3,8/3,4 5,2/5,1/4,9 7,5/7,4/7,3 11,4/11,3/11,3
C 1,8/1,5/NR 2,6/2,4/NR 3,3/3,2/2,8 4,9/4,8/4,6 8,5/8,4/8,3
D NR 1,9/1,7/NR 2,7/2,5/1,8 4,2/4,2/3,9 6,3/6,2/6,1
E/F NR NR NR NR NR
1600 A 5,5/5,4/5,2 5,7/5,6/5,4 7,1/7,0/6,8 10,1/10,0/9,9 15,7/15,7/15,6
B 3,7/3,6/3,3 3,9/3,8/3,4 5,2/5,2/4,9 7,5/7,5/7,3 11,4/11,4/11,3
C 1,9/1,6/NR 2,6/2,5/1,6 3,4/3,2/2,8 4,9/4,8/4,6 8,5/8,5/8,3
D 1,0/NR/NR 1,9/1,7/NR 2,7/2,6/1,9 4,3/4,2/3,9 6,3/6,3/6,1
E/F NR NR NR NR NR

© ISO 2011 – All rights reserved 13

---------------------- Page: 17 ----------------------
ISO 10803:2011(E)
Table B.1 (continued)
Allowable depth of cover
m
DN Soil group
( = 0,5/0,75/1,5)
Type 1 trench Type 2 trench Type 3 trench Type 4 trench Type 5 trench
1800 A 5,5/5,4/5,2 5,6/5,6/5,4 7,0/7,0/6,8 10,0/10,0/9,9 15,7/15,6/15,6
B 3,7/3,6/3,3 3,8/3,7/3,4 5,2/5,1/4,9 7,5/7,4/7,3 11,3/11,3/11,2
C 1,9/1,6/NR 2,6/2,4/1,7 3,3/3,2/2,8 4,9/4,8/4,6 8,5/8,4/8,3
D 1,0/NR/NR 1,9/1,7/NR 2,7/2,5/1,9 4,2/4,1/3,9 6,3/6,2/6,1
E/F NR NR NR NR NR
2000 A 5,5/5,4/5,2 5,6/5,6/5,4 7,0/7,0/6,8 10,0/10,0/9,9 15,7/15,6/15,6
B 3,7/3,6/3,3 3,8/3,7/3,5 5,2/5,1/4,9 7,5/7,4/7,3 11,3/11,3/11,2
C 1,9/1,6/NR 2,6/2,5/1,9 3,3/3,2/2,9 4,9/4,8/4,6 8,5/8,4/8,3
D 1,1/NR/NR 1,9/1,7/NR 2,7/2,6/2,0 4,2/4,2/3,9 6,3/6,2/6,1
E/F NR NR NR NR NR
2200 A 5,5/5,4/5,3 5,6/5,6/5,4 7,0/7,0/6,9 10,0/10,0/9,9 15,7/15,6/15,6
B 3,7/3,6/3,4 3,8/3,8/3,5 5,2/5,1/5,0 7,5/7,4/7,3 11,3/11,3/11,2
C 1,9/1,7/NR 2,6/2,5/2,0 3,3/3,3/2,9 4,9/4,8/4,6 8,5/8,4/8,3
D 1,1/NR/NR 2,0/1,8/NR 2,7/2,6/2,1 4,2/4,2/3,9 6,3/6,2/6,1
E/F NR NR NR NR NR
2400 A 5,5/5,4/5,3 5,6/5,6/5,4 7,0/7,0/6,8 10,0/10,0/9,9 15,6/15,6/15,6
B 3,7/3,6/3,4 3,8/3,8/3,5 5,2/5,1/5,0 7,4/7,4/7,3 11,3/11,3/11,2
C 1,9/1,7/NR 2,6/2,5/2,0 3,3/3,2/3,0 4,9/4,8/4,6 8,4/8,4/8,3
D 1,1/NR/NR 2,0/1,8/NR 2,7/2,6/2,2 4,2/4,2/3,9 6,3/6,2/6,1
E/F NR NR NR NR NR
2600 A 5,5/5,4/5,3 5,6/5,6/5,4 7,0/7,0/6,9 10,0/10,0/9,9 15,6/15,6/15,6
B 3,7/3,7/3,4 3,8/3,8/3,6 5,2/5,1/5,0 7,4/7,4/7,3 11,3/11,3/11,2
C 1,9/1,7/NR 2,6/2,5/2,1 3,3/3,3/3,0 4,9/4,8/4,7 8,4/8,4/8,3
D 1,2/NR/NR 2,0/1,8/NR 2,7/2,6/2,2 4,2/4,2/4,0 6,3/6,2/6,1
E/F NR NR NR NR NR
NR Not recommended
14 © ISO 2011 – All rights reserved

---------------------- Page: 18 ----------------------
ISO 10803:2011(E)
Table B.2 — Allowable depths of cover for C20 pipes conforming to ISO 2531 — Flexible lining
Allowable depth of cover
m
DN Soil group
( = 0,5/0,75/1,5)
Type 1 trench Type 2 trench Type 3 trench Type 4 trench Type 5 trench
700 A 7,2/7,1/7,0 7,4/7,4/7,2 9,2/9,1/9,0 12,9/12,9/12,8 20,0/20,0/19,9
B 5,0/4,9/4,6 5,2/5,1/4.8 6,9/6,8/6,6 9,7/9,7/9,6 14,6/14,6/14,5
C 2,8/2,6/NR 3,7/3,5/3,1 4,6/4,5/4,1 6,5/6,4/6,2 11,0/11,0/10,9
D 1,9/1,5/NR 2,9/2,7/NR 3,8/3,7/3,2 5,7/5,6/5,4 8,3/8,3/8,1
E/F NR NR NR NR NR
800 A 7,1/7,0/6,9 7,3/7,3/7,1 9,1/9,0/8,9 12,8/12,8/12,7 19,9/19,9/19,8
B 4,9/4,8/4,6 5,1/5,0/4,7 6,8/6,7/6,5 9,6/9,6/9,5 14,5/14,5/14,4
C 2,7/2,5/NR 3,6/3,4/2,9 4,5/4,4/4,0 6,4/6,3/6,1 10,9/10,9/10,7
D 1,8/1,4/NR 2,8/2,6/NR 3,7/3,6/3,1 5,6/5,5/3,0 8,2/8,1/8,0
E/F NR NR NR NR 1,4/NR/NR
900 A 7,0/7,0/6,8 7,3/7,2/7,0 9,0/8,9/8,8 12,8/12,7/12,6 19,8/19,8/19,7
B 4,9/4,8/4,5 5,0/4,9/4,7 6,7/6,6/6,5 9,6/9,5/9,4 14,4/14,4/14,3
C 2,6/2,4/NR 3,5/3,4/2,9 4,4/4,3/4,0 6,3/6,3/6,1 10,8/10,8/10,7
D 1,7/1,1/NR 2,7/2,5/NR 3,6/3,5/3,0 5,5/5,4/5,2 8,1/8,0/7,9
E/F NR NR NR NR 1,3/NR/NR
1000 A 7,0/7,0/6,8 7,3/7,2/7,0 9,0/8,9/8,8 12,8/12,7/12,6 19,8/19,8/19,7
B 4,9/4,8/4,5 5,0/4,9/4,7 6,7/6,7/6,5 9,6/9,5/9,4 14,4/14,4/14,
...