1、BRITISH STANDARD BS EN 1295-1:1997 Incorporating corrigenda May 2006 July 2008, February 2010 and March 2010 Structural design of buried pipelines under various conditions of loading Part 1: General requirements ICS 23.040.01 ,National foreword This British Standard is the UK implementation of EN 12
2、95-1:1997. The UK participation in its preparation was entrusted by Technical Committee B/505, Wastewater engineering, to Subcommittee B/504/505/1, General requirements for pipes and fittings. A list of organizations represented on this subcommittee can be obtained on request to its secretary. The a
3、ttached National Annex comprises the calculation procedure for the structural design of buried pipelines as practised in the UK. As the UK submission has been agreed, the BSI committee has included it to allow the UK pipe industry an early opportunity to view the calculation procedure. This publicat
4、ion does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. BS EN 1295-1:1997 This British Standard was published under the authority of the Standards
5、Board and comes into effect on 15 June 1998 BSI 2010 Amendments/corrigenda issued since publication Amd. No. Date Comments 16110 Corrigendum No. 1 31 May 2006 Corrections to National Annex 31 July 2008 Corrections to National Annex and alignment of BSI and CEN publication dates 28 February 2010 Pcrs
6、 changed to Pcra in NA. 6.2.3 ISBN 978 0 580 70689 9 31 March 2010 In NA. 6.2.3, P crachanged back to P crsin equation 21 and note CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels
7、1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1295-1 : 1997 E EUROPEAN STANDARD EN 1295-1 NORME EUROPE ENNE EUROPA ISCHE NORM July 1997 ICS 23.040.01 Descriptors: Sanitation, water supply, water removal, water pipelines, bur
8、ied pipes, pressure pipes, sewage, computation, mechanical strength, loads: forces English version loading Part 1: General requirements Calcul de re sistance me canique des canalisations enterre es sous diverses conditions de charge Partie 1: Prescriptions ge ne rales Statische Berechnung von erdver
9、legten Rohrleitungen unter verschiedenen Belastungsbedingungen Teil 1: Allgemeine Anforderungen This European Standard was approved by CEN on 1997-06-29. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the sta
10、tus of a 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 European Standard exists in three official versions (English, French, German). A
11、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, Czech Republic, Denmark, Finland,
12、France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Structural design of buried pipelines under various conditions ofPage 2 Foreword This European Standard has been prepared by Technical Committee CEN/TC 165, Was
13、te water engineering, the Secretariat of which is held by DIN. 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 January 1998, and conflicting national standards shall be withdrawn at the latest by J
14、anuary 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands
15、, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. This standard is intended for use in conjunction with the series of product standards covering pipes of various materials for the water industry. This standard comprises two Parts: Part 1: General requirements, dealing with the r
16、equirements for structural design of pipelines and giving the basic principles of the nationally established methods of design; Part 2: Summary of the nationally established methods of design, giving an overview of these methods as prepared by the various countries where they are in use. Contents Pa
17、ge Foreword 2Introduction 3 1 Scope 3 2 Normative references 3 3 Definitions 3 3.1 Installation terms 3 3.2 Design terms 4 4 Requirements 4 5 Basis of design procedures 4 5.1 General 4 5.2 External loads 5 5.3 Limit states 5 5.4 Longitudinal effects 5 6 Additional considerations for pressure pipelin
18、es 5 6.1 General 5 6.2 Stresses and strains resulting from simultaneous loads 5 6.3 Effect of pressure on deformation 6 6.4 Buckling of pressure pipes 6 6.5 Thrusts and longitudinal stresses 6 7 Influence of construction procedures 6 7.1 General 6 7.2 Trenching procedures 6 7.3 Pipe bedding 6 7.4 Fi
19、lling procedures 7 8 Design philosophies and factors of safety 7 Annexes A (informative) Pipe definition according to cross-sectional behaviour 7 B (informative) Nationally established methods of design 7 B.1 Identification of methods and addresses where they are available 8 B.1.1 Austria 8 B.1.2 Be
20、lgium 8 B.1.3 Denmark 8 B.1.4 Finland 8 B.1.5 France 8 B.1.6 Germany 8 B.1.7 Netherlands 9 B.1.8 Norway 9 B.1.9 Spain 9 B.1.10 Sweden 9 B.1.11 Switzerland 10 B.1.12 United Kingdom 10 B.2 Description of methods 11 B.2.1 Austria 11 B.2.2 Belgium 12 B.2.3 Denmark 12 B.2.4 Finland 13 B.2.5 France 14 B.2
21、.6 Germany 14 B.2.7 Netherlands 15 B.2.8 Norway 15 B.2.9 Spain 15 B.2.10 Sweden 16 B.2.11 Switzerland 17 B.2.12 United Kingdom 17 BS EN 1295-1:1997 EN 1295-1:1997 BSI 2009Page 3 1 Surface 2 Bottom of road or railway construction, if any 3 Trench walls 4 Main backfill (3.6) 5 Initial backfill (3.5) 6
22、 Sidefill (3.12) 7 Upper bedding 8 Lower bedding 9 Trench bottom 10 Depth of cover (3.3) 11 Depth of bedding (3.1) 12 Depth of embedment (3.4) 13 Trench depth (3.13) a Depth of lower bedding b Depth of upper bedding c Depth of initial backfill NOTE. The terms in figure 1 are the same as in prEN 1610
23、. Figure 1. Trench installation 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 many years. Whilst many common features exist between the
24、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 t
25、o 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 European Standard. In accordance with this two stage approach, the joint working group, at its initial me
26、eting, resolved first to produce an EN 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 standard represents the implementation of the fi
27、rst part of that resolution. 1 Scope This standard specifies the requirements for the structural design of water supply pipelines, drains and sewers, and other water industry pipelines, whether operating at atmospheric, greater or lesser pressure. In addition, this standard gives guidance on the app
28、lication of the nationally established methods of design declared by and used in CEN member countries at the time of preparation of this standard. This guidance is an important source of design expertise, but it cannot include all possible special cases, in which extensions or restrictions to the ba
29、sic 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 guide can only provide general indications and
30、advice. This Part of the standard specifies the requirements for structural design and indicates the references and the basic principles of the nationally established methods of design (see annexes A and B). 2 Normative references This European Standard incorporates, by dated or undated reference, p
31、rovisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of the publications apply to this European Standard only when incorporated in it
32、 by amendment or revision. For undated references, the latest edition of the publication referred to applies. prEN 1610 Construction of pipelines for drains and sewers 3 Definitions For the purposes of this standard, the following definitions apply (see also annex A). 3.1 Installation terms Installa
33、tion terms are given in figure 1. The same terms apply for embankment installations and for trenches with sloping sides. BS EN 1295-1:1997 EN 1295-1:1997 BSI 2009Page 4 3.1.1 compaction Deliberate densification of soil during the construction process. 3.1.2 consolidation Time-dependent densification
34、 of soil by processes other than those deliberately applied during construction. 3.1.3 embedment Arrangement and type(s) of material(s) around a buried pipeline which contribute to its structural performance. 3.2 Design terms 3.2.1 bedding factor Ratio of the maximum design load for the pipe, when i
35、nstalled with a particular embedment, to the test load which produces the same maximum bending moment. 3.2.2 design pressure (DP) Maximum operating internal pressure of the system or of the pressure zone fixed by the designer considering future developments but excluding surge. 3.2.3 load bearing ca
36、pacity Load per unit length that a particular combination of pipe and embedment can sustain without exceeding a limit state. 3.2.4 maximum design pressure (MDP) Maximum operating internal pressure of the system or of the pressure zone fixed by the designer considering future developments and includi
37、ng surge, where: MDP is designated MDPa when there is a fixed allowance for surge; MDP is designated MDPc when the surge is calculated. 3.2.5 silo effect Effect whereby lateral earth pressure in trench backfill causes friction at the trench wall to carry part of the weight of the backfill. 3.2.6 soi
38、l-structure interaction Process whereby the deformations of soil and/or pipe caused by the contact and reaction pressures between a pipe and the surrounding soil distribute the pressures to achieve equilibrium. 3.2.7 system test pressure (STP) Hydrostatic pressure applied to a newly laid pipeline in
39、 order to ensure its integrity and tightness. 4 Requirements 4.1 All pipelines shall be designed to withstand the various loadings to which they are expected to be subjected, during construction and operation, without detriment to their function and to the environment. 4.2 The future owner of the pi
40、peline is free to specify the appropriate method of design to be adopted. 4.3 The designer shall determine whether or not the pipeline comes within the scope of the methods covered by this standard. 4.4 The design adopted shall be such that construction may be carried out safely and so as to ensure
41、that the design assumptions regarding the influence of construction procedures and soil characteristics will be satisfied. 4.5 Subject to the other requirements of clause 4, design should be carried out preferably using in its entirety one of the methods in annex B of this standard. 4.6 Methods of d
42、esign, in accordance with annex B, when presented in the form of tables, charts or computer programmes, shall be deemed equivalent to a full calculation, provided that any simplification does not reduce the level of safety to below that which would be obtained by full design. Outputs from computer p
43、rogrammes shall be capable of verification. 4.7 Where a design method other than one of those in annex B is employed, the designer shall satisfy himself that the method constitutes a coherent system and provides the level of safety required. 4.8 Account shall be taken of the probable consequences of
44、 pipeline failure in establishing the acceptable level of safety. 4.9 The values adopted for all variables, including factors of safety, shall be in accordance with the method used. 5 Basis of design procedures 5.1 General Whilst there are differences between some of the established national design
45、procedures, there are no differences in respect of the fundamental basis of design, which is the interactive system consisting of the pipe and the surrounding soil. The external loadings to be considered shall include that due to the backfill, that due to the most severe surface surcharge or traffic
46、 loading likely to occur, and those due to any other causes, producing a loading of significant magnitude such as self weight of the pipe and water weight, as appropriate. The internal pressure in the pipeline, if different from atmospheric, shall also be treated as a loading. The design of the pipe
47、line, and its embedment, shall provide an adequate level of safety against the appropriate ultimate limit state being exceeded. In addition, the design loading shall not result in any appropriate serviceability limit state being exceeded. BS EN 1295-1:1997 EN 1295-1:1997 BSI 2009Page 5 5.2 External
48、loads Account shall be taken of the effect of the stiffness of the pipe and the stiffness of the surrounding soil. Where appropriate, account shall be taken of the effects of trench construction, of groundwater and of time dependent influences. The design should take into consideration, however, the
49、 possible effect on trench conditions of any further planned works. The effective pressure due to the backfill and any distributed surface loads shall be calculated on the basis of the principles of soil-structure interaction. The pressure exerted on pipelines by concentrated surface surcharges, such as vehicle wheels, shall be calculated in accordance with a method based on Boussinesq, and account shall be taken of im
