BS ISO 10803-2012 Design method for ductile iron pipes《球墨铸铁管的设计方法》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 10803:2011Design method for ductile ironpipesBS ISO 10803:2011 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 10803:2011.The UK par

2、ticipation in its preparation was entrusted to TechnicalCommittee PSE/10, Iron pipes and fittings.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are respons

3、ible for its correctapplication. The British Standards Institution 2012ISBN 978 0 580 65917 1ICS 23.040.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 Januar

4、y 2012.Amendments issued since publicationDate Text affectedBS ISO 10803:2011Reference numberISO 10803:2011(E)ISO 2011INTERNATIONAL STANDARD ISO10803Second edition2011-12-01Design method for ductile iron pipes Mthode de calcul des tuyaux en fonte ductile BS ISO 10803:2011ISO 10803:2011(E) COPYRIGHT

5、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 IS

6、Os 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 copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2011 All rights reservedBS ISO 10803:2011ISO 10803:2011(E) ISO 2011 All rights r

7、eserved iiiContents 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 cove

8、r 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 BS ISO 10803:2011ISO 10803:2011(E) iv ISO 2011 All rights reservedForewor

9、d 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 technica

10、l 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 ele

11、ctrotechnical 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 th

12、e 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 ide

13、ntifying 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 techni

14、cally revised. BS ISO 10803:2011INTERNATIONAL STANDARD ISO 10803:2011(E) ISO 2011 All rights reserved 1Design 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 pres

15、sure, 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 (includin

16、g 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 instal

17、lation 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 op

18、erating 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

19、 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. BS ISO 10803:2011ISO 10803:2011(E) 2 ISO 2011 All rights reserved3.4 embed

20、ment 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

21、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

22、 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 al

23、lowable 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

24、 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 mini

25、mum 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

26、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 cond

27、itions 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

28、 certain countries, national standards or regulations can specify other design procedures. BS ISO 10803:2011ISO 10803:2011(E) ISO 2011 All rights reserved 35 Design for internal pressure 5.1 Design equation for wall thickness The minimum wall thickness of pipes, emin, shall be not less than 3 mm (as

29、 specified in ISO 2531) or 2,4 mm (ISO 7186) and shall be determined using Equation (1): minmPFA SF DE20 (PFA SF)eR(1) where eminis the minimum pipe wall thickness to resist hoop stress due to internal pressure, in millimetres; PFAis the allowable operating pressure, in bar1)(see 5.2); SF is the des

30、ign safety factor (see 5.2); DE is the nominal pipe external diameter, in millimetres (see Annex A); Rmis the minimum ultimate tensile strength of the ductile iron, in megapascals (Rm 420 MPa in ISO 2531 and ISO 7186). Nominal wall thickness, enom, of the pipe is calculated as given by Equation (2):

31、 nom min1,3 0,001DNee (2)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 accor

32、dance with ISO 7186 are given in Table A.2. 5.2 Design safety factors The minimum pipe wall thickness, emin, shall be calculated with a design safety factor of 2,5 for the maximum allowable operating pressure (i.e. PMA as indicated in ISO 2531 and ISO 7186) and a design safety factor of 3 for the al

33、lowable 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

34、 6.1 Design equation x100 80,061KqSE(3) or 1) 100 kPa = 1 bar = 0,1 MPa; 1 MPa = 1 N/mm2. BS ISO 10803:2011ISO 10803:2011(E) 4 ISO 2011 All rights reservedx8 0,061100SEqK(3) where is the pipe diametral deflection, in percent of external diameter, D; Kxis the deflection coefficient depending on beddi

35、ng reaction angle; q is the vertical pressure at pipe crown due to all external loads, in megapascals; S is the pipe diametral stiffness, in megapascals, 3()EISD where E is the modulus of elasticity of the pipe wall material, in megapascals (170 000 MPa for ductile iron); I 3stiff12eis the second mo

36、ment of area of the pipe wall per unit length, in millimetres to the third power; D is the mean diameter of pipe in millimetres; stiffDE ,eDE is the nominal pipe external diameter as specified in ISO 2531 and ISO 7186, in millimetres; estiffis the average of the minimum pipe wall thickness of the pi

37、pe and nominal wall thickness of 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 Kxare given in Table 1 for each trench type and soil group. NOTE The desig

38、n 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;

39、causes a pipe deflection, which gives rise to a horizontal reaction pressure at pipe sides, parabolically distributed over an angle of 100. BS ISO 10803:2011ISO 10803:2011(E) ISO 2011 All rights reserved 5Key 1 vertical pressure, q 2 lateral reaction pressure = 0,01 E 3 vertical reaction pressure =

40、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: 12qq q (4) where q1is the pressure from earth loads; q2is the pressure from traffic

41、loads; NOTE The pressure from traffic loads, q2, is greater than that from normal static loads applied to the ground surface; 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.

42、e. ()qfH (5) Equating this to Equation (3) (see 6.1): x(8 0,061 )()() (10)SEfHK (6) 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. BS ISO 10803:2011ISO 10803:2011(E) 6 ISO 2011 All rights reser

43、ved6.2.2 Pressure from earth loads Equation (7) shall be used to calculate q1from the weight of the earth prism immediately above the pipe: 10,001qH(7) where q1is the pressure at pipe crown, in megapascals; is the unit weight of the backfill, in kilonewtons per cubic metre; H is the height of cover

44、(distance from pipe crown to ground surface), in metres. In the absence of other data, the unit weight of the soil is taken as being equal to 20 kN/m3in order to cover the vast majority of cases. If a preliminary geotechnical survey determines that the actual unit weight of the backfill is less than

45、 20 kN/m3, the actual value may be used for determining q1. If, however, it appears that the actual value is more than 20 kN/m3, the actual value should be used. 6.2.3 Pressure from traffic loads The value of q2shall be calculated using Equation (8), based on wheel load taken from national and/or lo

46、cal applicable standards and regulations. 420,04 (1 2 10 DN)qH (8) where q2is the pressure at pipe crown, in megapascals; 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 c

47、ases; 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: 100P (9) where P is the wheel load, in kilonewtons, for a particular typ

48、e 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. BS ISO 10803:2011ISO 10803:2011(E) ISO 2011 All rights reserved 7NOTE 2 For pipelines under railroads o

49、r 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