# PD CEN TR 01295-2-2005 (2006)

PUBLISHED DOCUMENT PD CEN/TR 1295-2:2005 Structural design of buried pipelines under loading — Part 2: Summary of nationally established methods of design ICS 23.040.01 various conditions of PD CEN/TR 1295-2:2005 This Published Document was published under the authority of the Standards Policy and Strategy Committee on 31 May 2006 © BSI 2006 ISBN 0 580 48585 4 National foreword This Published Document is the official English language version of CEN/TR 1295-2:2005. The UK participation in its preparation was entrusted to Technical Committee B/505, Waste water engineering, which has the responsibility to: — aid enquirers to understand the text; — present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; — monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a Published Document does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the CEN/TR title page, pages 2 to 111 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsTECHNICALREPORT RAPPORTTECHNIQUE TECHNISCHERBERICHT CEN/TR12952 August2005 ICS23.040.01 EnglishVersion Structuraldesignofburiedpipelinesundervariousconditionsof loadingPart2:Summaryofnationallyestablishedmethodsof design Calculderésistancemécaniquedescanalisations enterréessousdiversesconditionsdechargePartie2: Résumédesméthodesnationalesdedimensionnement StatischeBerechnungvonerdverlegtenRohrleitungen unterverschiedenenBelastungsbedingungenTeil2: Zusammenstellungnationaleingeführter Berechnungsverfahren ThisTechnicalReportwasapprovedbyCENon28February2005.IthasbeendrawnupbytheTechnicalCommitteeCEN/TC165. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITÉEUROPÉENDENORMALISATION EUROPÄISCHESKOMITEEFÜRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels ©2005CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.CEN/TR12952:2005:ECEN/TR 1295-2:2005 2 Contents Foreword 4 Introduction5 1 Scope .6 2 Normative references .6 3 Terms and definitions.6 4 Additional details about established methods .6 Annex A (informative) Summary of Methods of different countries.7 A.1 Austria .7 A.1.1 General remarks7 A.1.2 Differences between “option 1“ and ÖNORM B 5012.7 A.1.3 Principles.8 A.2 Belgium9 A.2.1 General 9 A.2.2 Flowchart.9 A.2.3 Design, equations, tables and charts, symbols and abbreviations 9 A.3 Denmark .21 A.3.1 General 21 A.3.2 Charges .24 A.3.3 Safety .26 A.3.4 Partial safety factors.27 A.3.5 Calculations. 27 A.4 France 29 A.4.1 Scope .29 A.4.2 Original features of the method .29 A.4.3 Description 29 A.4.4 Example of calculation .37 A.5 Germany 39 A.5.1 Introduction .39 A.5.2 Types of soil 39 A.5.3 Live loads 40 A.5.4 Effects of the installation on the structural calculation .44 A.5.5 Loading44 A.5.6 Load distribution.45 A.5.7 Pressure distribution at pipe circumference 50 A.5.8 Sectional forces, stresses, strains, deformations51 A.5.9 Dimensioning 52 A.6 Netherlands .56 A.6.1 General 56 A.6.2 Earth load 56 A.6.3 Evenly distributed surface load .57 A.6.4 Traffic loads.57 A.6.5 Heavy transport.57 A.6.6 Loads form external and internal water pressure 58 A.6.7 Thermal loading 58 A.6.8 Moments and normal forces 59 A.6.9 Calculation model for a concrete pipe 62 A.6.10 Recommended design values69 A.7 Norway.73 A.7.1 Types of loads.73 A.7.2 Soil loads.73 A.7.3 Self weight of pipe 73 A.7.4 Weight of water .74 CEN/TR 1295-2:2005 3 A.7.5 Traffic load.74 A.7.6 Load distribution and bedding reaction74 A.7.7 Safety analysis 74 A.7.8 Structural design.74 A.8 Sweden 75 A.8.1 Design of buried plastic pipes .75 A.8.2 Calculation method for rigid pipes 83 A.9 United Kingdom 86 A.9.1 General description 86 A.9.2 Calculation procedures 86 A.9.3 Rigid pipes.87 A.9.4 Semi-rigid pipes 90 A.9.5 Flexible pipes 93 Bibliography.110 4 Foreword This Technical Report (CEN/TR 1295-2:2005) has been prepared by Technical Committee CEN/TC 165 “Wastewater engineering”, the secretariat of which is held by DIN. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This Technical Report was prepared by a Joint Working Group (JWG 1) of Technical Committees TC 164, Water supply, the secretariat of which is held by AFNOR, and TC 165, Waste water engineering, the secretariat of which is held by DIN. This Technical Report is intended for use in conjunction with the series of product standards covering pipes of various materials for the water industry. This Technical Report includes an Informative Annex A in which are included additional details about the nationally established methods of design declared, submitted by and used in member countries, and collated by the Joint Working Group. CEN/TR 1295-2:20055 Introduction The structural design of buried pipelines constitutes a wide ranging and complex field of engineering, which has been the subject of extensive study and research, in many countries over a period of very many years. Whilst many common features exist between the design methods which have been developed and established in the various member countries of CEN, there are also differences reflecting such matters as geological and climatic variations, as well as different installation and working practices. In view of these differences, and of the time required to develop a common design method which would fully reflect the various considerations identified in particular national methods, a two stage approach has been adopted for the development of this document. In accordance with this two stage approach, the Joint Working Group, at its initial meeting, resolved “first to produce a document giving guidance on the application of nationally established methods of structural design of buried pipelines under various conditions of loading, whilst working towards a common method of structural design“. This document represents the full implementation of the first part of that resolution. CEN/TR 1295-2:20056 1 Scope In addition to EN 1295-1, this Technical Report gives additional guidance when compared with EN 1295-1 on the application of the nationally established methods of design declared by and used in CEN member countries at the time of preparation of this document (see informative Annex A). This Technical Report is an important source of design expertise, but it cannot include all possible special cases, in which extensions or restrictions to the basic design methods may apply. Since in practice precise details of types of soil and installation conditions are not always available at the design stage, the choice of design assumptions is left to the judgement of the engineer. In this connection the document can only provide general indications and advice. 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. EN 1295-1, Structural design of buried pipelines under various conditions of loading — Part 1: General requirements 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 1295-1 apply. 4 Additional details about established methods Annex A gives for several countries details about the established methods of design declared, submitted by and used in member countries. CEN/TR 1295-2:20057 Annex A (informative) Summary of Methods of different countries A.1 Austria A.1.1 General remarks The Austrian Standard Őnorm B 5012:2005 is based on the “option 1“ contained in CEN/TR 1295-3. This “option 1“ had been prepared by the TG1 of the CEN/TC164-165/JWG1 as a result of thorough study of the subject and long-lasting consultations carried out from 1992 onwards. Although the design method described in “option 1“ was mainly based on two recognised and well-tested “national methods“, the German ATV-DVWK-A 127 and the (former) Austrian ÖNORM B 5012-1 and – 2, some new assumptions had to be incorporated in the re-drafted “option 1“ in order to consider the most recent experience gained in this domain. Therafter, it was of course also necessary to prove the correctness of the newly made assumptions by means of comprehensive field testing. This particular kind of testing was done during the period from 2000 to 2004. The tests results obtained were already incorporated in the ÖNORM B 5012 a revision of the former parts 1 and 2 of this standard. Therefore the ÖNORM B 5012:2005 represents a calculation method which is based on the most recent experience in this field, but it still complies with the calculation principles elaborated by “JWG 1“ regarding the “option 1“ of CEN/TR 1295-3. A.1.2 Differences between “option 1“ and ÖNORM B 5012 The ÖNORM B 5012 differs in the following points from “option 1“: 1) Two different applications of ÖNORM B 5012 enable to make i) calculations for pipe design and ii) back-calculations of failure situations For the pipe design the soil moduli proposed in “option 1“ (Table 4) shall be reduced by the factor 0,5, whereas for back-calculations the unchanged soil moduli from “option 1“ should be used. The purpose for this distinction is the following: The results of calculations for the pipe design should be close to the 95 % fractile of the scattering design values, like deflection, stress or strain. Then the required safety or failure probability is assured by using the safety factors proposed in ÖNORM B 5012. However, for back-calculations of failure situations the calculation results should be as close as possible to the mean value of the measured values. 2) Factor f R,GWis changed in ÖNORM B 5012 in comparison to “option 1“ ( compare equation 23 in “option 1“ and ÖNORM B 5012). 3) The soil pressure ratios K 1and K 2are partly changed (compare Table 11 in “option 1“ and ÖNORM B 5012). CEN/TR 1295-2:20058 4) The recommended support angles α vare partly changed (compare Table 13 in “option 1“ and ÖNORM B 5012). 5) In ÖNORM B 5012 the horizontal bedding stiffness S Bhand factor ζ is calculated in a clearer and easier way than in “option 1“ (compare 8.3.2 in “option 1“ and ÖNORM B 5012). 6) The estimated values of relative initial ovalization δ v,ioin “option 1“ are reduced in ÖNORM B 5012 by the factor 0,5 (compare Tables 19 and 20 in “option 1“ with Table 18 and 19 in ÖNORM B 5012). 7) In ÖNORM B 5012 it is proposed to use the theory 2 ndorder calculation more consequently than in “option 1“ (in ÖNORM for flexible pipes with deflections greater than 1 % in comparison to 5 % in “option 1“). A.1.3 Principles Like “option 1“, the ATV-DVWK-A 127 and the ÖNORM model the calculation system of ÖNORM B 5012 is based on the model of the embedded circular or non circular ring. The pipe-soil interaction is taken into account by the following interpretations: 1) In vertical direction: Using the shear-stiff beam model above the pipe for the calculation of the vertical loading due to the earth weight and uniformly distributed surcharge; 2) In horizontal direction: Using the compatibility condition of the horizontal pipe and soil movements taking into account all loads considered in the calculation (e.g. for the calculation of the horizontal bedding reaction pressures). Further descriptions of details about the principles and the calculation method are stated in CEN/TR 1295-3. CEN/TR 1295-2:20059 A.2 Belgium A.2.1 General Calculation procedure of the ISO 2785: Directives for selection of asbestos-cement pipes subject to external loads with or without internal pressure. A.2.2 Flowchart A.2.3 Design, equations, tables and charts, symbols and abbreviations A.2.3.1 Symbols and abbreviations A width of uniform surcharge of small extent, in metres; CEN/TR 1295-2:200510 a distance between two wheels on a single axle of a truck, in metres; B width of trench at the crown of the pipe, in metres; B’ distance of the spring-line of a pipe from the wall of the trench in which it is buried, in metres; h distance between two wheels of two different axles of a truck, in metres; c diagonal distance between two wheels of two different axles of a truck, in metres; C.C 90 earth-load coefficient for a trench with vertical walls; C cload coefficient for superimposed concentrated moving loads; C dload coefficient for uniform surcharges of small extent; C nload coefficient for uniform surcharges of large extent; C v , C d1 , C v2 , C v3coefficients of vertical deformation of pipe; C h2 , C h3coefficients of horizontal deformation of pipe; d nominal or internal diameter of pipe, in millimetres; D external diameter of pipe, in metres; e base of natural logarithms; E modulus of elasticity, in Newtons per square millimetre; E pmodulus of elasticity of pipe, in Newtons per square millimetre; E smodulus of compression of soil, in Newtons per square millimetre; E tmodulus of elasticity of road construction material, in Newtons per square millimetre; E 1 , E 2 , E 3 , E 4moduli of compression of soil and backfill in various zones of the trench, in Newton per square millimetre; H, H 1 , H 2heights of earth cover of a pipe, in metres; H eequivalent height of earth cover a pipe laid under a paved road, in metres; HT heavy truck; I modulus of inertia of the wall of the pipe per unit length, in cubic millimetres; k factor of ring-bending moment; k v1 , k h1 , k hp , k wfactors of ring-bending moments due to vertical and horizontal loads, horizontal reaction pressure and water-load respectively; K 1 , K 2coefficients of lat