1、 ISO 2017 Plastics piping systems General rules for structural design of glass- reinforced thermosetting plastics (GRP) pipes Part 1: Buried pipes Systmes de canalisation en matires plastiques - Rgles gnrales pour la conception structurelle destubes et raccords plastiques thermodurcissables renforcs
2、 de verre (PRV) Partie 1: Tubes enterr TECHNICAL SPECIFICATION ISO/TS 20656-1 Reference number ISO/TS 20656-1:2017(E) First edition 2017-06 ISO/TS 20656-1:2017(E)ii ISO 2017 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in Switzerland All rights reserved. Unless otherwise spec
3、ified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or I
4、SOs member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.org ISO/TS 20656-1:2017(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms
5、 and definitions . 1 4 Partial factor method . 2 4.1 General . 2 4.2 Reliability index, .2 4.3 Sensitivity index, 4 4.4 Quality management 4 5 Partial factors for effects of actions 5 5.1 General . 5 5.2 Partial factors for internal pressure . 5 5.2.1 General 5 5.2.2 Model uncertainty 6 5.2.3 Uncert
6、ainty of pressure . 7 5.2.4 Uncertainty of long-term pressure. 7 5.2.5 Uncertainty of short-term pressure 8 5.2.6 Uncertainty of thickness and E-modulus 9 5.2.7 Uncertainty of diameter 9 5.2.8 Combined uncertainty and partial factor for effects of pressure . 9 5.3 Partial factors for soil and traffi
7、c load .12 5.3.1 General.12 5.3.2 Uncertainty of installation parameters .14 5.3.3 Uncertainty of deflection model 14 5.3.4 Uncertainty in traffic load .15 5.3.5 Uncertainty in pipe stiffness .15 5.3.6 Uncertainty of deflection measurement .15 5.3.7 Deflection lag factor .15 5.3.8 Uncertainty of mod
8、el Stress and strain calculation .15 5.3.9 Strain assessment through curvature measurement 16 5.3.10 Combined uncertainty of installation parameters 16 5.3.11 Partial factors for effects of bending 16 5.4 Combined effects of pressure and bending .17 6 Partial factors for resistance .17 6.1 Concept .
9、17 6.2 Design value for resistance 18 6.2.1 General.18 6.2.2 Long-term resistance and conversion factor, . 18 6.2.3 Short-term resistance .19 Annex A (normative) Recommended values for pressure safety factors 21 Annex B (normative) Test data analysis .22 Bibliography .24 ISO 2017 All rights reserved
10、 iii Contents Page ISO/TS 20656-1:2017(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
11、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 Electr
12、otechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of
13、 ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives). 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 h
14、eld responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents). Any trade name used in this document is infor
15、mation given for the convenience of users and does not constitute an endorsement. For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (
16、WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: w w w . i s o .org/ iso/ foreword .html. This document was prepared by ISO/TC 138, Plastics pipes, fittings and valves for the transport of fluids, SC 6, Reinforced plastics pipes and fittings for all applications. A lis
17、t of all the parts in the ISO 20656- series, can be found on the ISO website.iv ISO 2017 All rights reserved ISO/TS 20656-1:2017(E) Introduction This document provides general rules for structural design of buried glass-reinforced thermosetting plastics (GRP) pipes. It provides the necessary link be
18、tween the requirements for safety, serviceability and durability of GRP pipe construction products and the technical provisions for civil works. The basis for design of structures, as specified in ISO 2394 and Eurocode EN 1990, are addressed in this document by providing partial factors for effects
19、of actions and resistance for buried GRP pipes. ISO 2017 All rights reserved v Plastics piping systems General rules for structural design of glass-reinforced thermosetting plastics (GRP) pipes Part 1: Buried pipes 1 Scope This document describes how partial factors for buried GRP pipes are develope
20、d, and are primarily intended to define the necessary safety measures for GRP pipes that meet the requirements of ISO 10639, ISO 10467 and ISO 25780, and EN 1796 and EN 14364. The same methodology can be utilised for other pipe product standards, although other parameters would apply. 2 Normative re
21、ferences The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendment
22、s) applies. ISO 2394:2015, General principles on reliability for structures ISO 10639, Plastics piping systems for pressure and non-pressure water supply Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin ISO 10467 , Plastics piping systems for pressure a
23、nd non-pressure drainage and sewerage Glass-reinforced thermosetting plastics (GRP) systems based on unsaturated polyester (UP) resin ISO 25780, Plastics piping systems for pressure and non-pressure water supply, irrigation, drainage or sewerage Glass-reinforced thermosetting plastics (GRP) systems
24、based on unsaturated polyester (UP) resin Pipes with flexible joints intended to be installed using jacking techniques EN 1796, Plastics piping systems for water supply with or without pressure Glass-reinforced thermosetting plastics (GRP) based on unsaturated polyester resin (UP) EN 1990:2002, Euro
25、code Basis of structural design EN 14364, Plastics piping systems for drainage and sewerage with or without pressure Glass-reinforced thermosetting plastics (GRP) based on unsaturated polyester resin (UP) Specifications for pipes, fittings and joints EN/TS 14632, Plastics piping systems for drainage
26、, sewerage and water supply, pressure and non- pressure Glass-reinforced thermosetting plastics (GRP) based on unsaturated polyester resin (UP) Guidance for the assessment of conformity 3 T erms a nd definiti ons For the purposes of this document the terms and definitions given in ISO 2394 and EN 19
27、90 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ TECHNICAL SPECIFICATION ISO/TS 20656-1:2017(E) ISO 2017 All rights reserved 1 ISO/TS 20656-1:2017(E) ISO Online browsing pl
28、atform: available at h t t p :/ www .iso .org/ obp 4 Partial factor method 4.1 General The procedures used here follow the methodology for establishing partial factors for effects of actions and structural resistance as specified in ISO 2394 and EN 1990. The procedure followed is the semi- probabili
29、stic method (ISO 2394:2015, Clause 9 and EN 1990, Clause 6), where characteristic values of actions are defined, and these design values are determined based on the uncertainties involved, both in terms of actions, material properties and environment. The partial factors are the ratio between the ch
30、aracteristic values and the design values. The process consists of minimising the risk involved compared with perceived costs, and defined probability of failure, using level II of the first order reliability method (FORM, Level II). In this Clause the method is described briefly as it applies for b
31、uried flexible pipes. For a full explanation of the methodology, refer to ISO 2394 and EN 1990. The method for establishing partial factors for resistance is based on ISO 2394, 9.4.2 (with reference to Annex C), as EN 1990, 6.3.3, 6.3.4 and 6.3.5 (with reference to Annex D). The principles are the s
32、ame in both standards. 4.2 Reliability index, The measure of reliability is conventionally defined by the reliability index, , which is related to the probability of failure, P f , by: P f (1) where is the cumulative distribution function of the standardised normal distribution. The relation between
33、 the probability of failure, P f , and the reliability index, , is given in Table 1. Table 1 Relationship between probability of failure and reliability index P f 10 -1 10 -2 10 -3 10 -4 10 -5 10 -6 10 -7 1,28 2,32 3,09 3,72 4,27 4,75 5,20 The probability of failure, P f , is expressed through a per
34、formance function, g, such that a structure is considered to survive if g 0 and fail if g 0: (2) where g is the performance function with: (3) where R is the resistance; E is the effect of actions; R, E and g are random variables.2 ISO 2017 All rights reserved ISO/TS 20656-1:2017(E) For a normal dis
35、tribution the reliability index is: g g(4) where g is the mean value of g; g is the standard deviation. We thus have: and . Using this function, the partial factors are established, based on the uncertainties associated with the effects of actions and the uncertainties of resistance. Since the short
36、-term resistance of plastics is considerably higher than the long-term resistance, the partial factors for effects of actions need to be determined for both cases, i.e. both for incidental actions and sustained actions. Partial factors for resistance are determined for short-term material properties
37、 and are converted to long-term material properties as described in Clause 6. The design value for a normal distribution is (see EN 1990:2002, Table C.3 and ISO 2394:2015, Clause E.6): (5) where is the mean value; is the sensitivity index; is the reliability index; is the standard deviation; V is th
38、e coefficient of variation. Both EN 1990 and ISO 2394 define target reliabilities based on consequences of failure. In addition, the ISO 2394 includes the relative cost of safety measure as part of the assessment. Table 2 shows the consequence classes as defined in EN 1990. ISO 2017 All rights reser
39、ved 3 ISO/TS 20656-1:2017(E) T a b l e 2 C o n s e q u e n c e c l a s s e s a s d e f i n e d i n E N 1 9 9 0 : 2 0 0 2 , T a b l e B . 1 Consequence class Description Examples of pipelines Minimum value for CC3 High consequence for loss of human life, or eco- nomic, social or environmental consequ
40、ences very great. Significant damage to the qualities of the environment contained at national scale but spreading significantly beyond the surroundings of the failure event and which can only be partly restored in a matter of months. Major water supply and sewerage pipes within cities, transmission
41、 lines without back-up, oil and gas pipelines. 4,2 CC2 Medium consequence for loss of human life, econom- ic, social or environmental consequences consid- erable. Damage to the qualities of the environment limited to the surroundings of the failure event and which can be restored in a matter of week
42、s. Major water supply and sewerage pipes within cities, transmission lines with back-up, penstocks where flooding can wreak havoc. 3,7 CC1 Low consequence for loss of human life and eco- nomic, social or environmental consequences small or negligible. Damage to the environment of an order which can
43、be restored completely in a matter of weeks. Irrigation, small and remote penstocks. 3,1 is based on a 50 year design life. 4.3 Sensitivity index, The FORM analysis as defined in ISO 2394 includes a sensitivity factor for the independent random variables for actions and resistance. The sensitivity f
44、actors are summarised in ISO 2394:2015, Table E.3, and repeated here in Table 3. Table 3 Sensitivity factors for actions and resistance X i i Dominating resistance parameter 0,8 Other resistance parameters 0,4 0,8 = 0,32 Dominating load parameter 0,7 Other load parameters 0,4 0,7 = 0,28 For non-pres
45、sure or low pressure pipes the deflection will be the dominating load parameter. For high pressure pipes the pressure will be the dominating load parameter. The corresponding resistance parameters apply. 4.4 Quality management Quality management shall follow the rules in ISO 2394:2015, Annex A. Thes
46、e can be directly related to the consequence classes, as shown in Table 4. In case of buildings, engineering works and engineering systems where high consequence for loss of human life or economic, social, or environmental consequences are involved, i.e. public buildings where consequences of failur
47、e are high (e.g. a concert hall, grandstand, high-rise building, critical bearing elements), a quality level QL3 shall be applied. The choice of the required quality level can be based on reliability-based methods. See Table 4 for quality levels based on consequence class.4 ISO 2017 All rights reser
48、ved ISO/TS 20656-1:2017(E) Table 4 Quality levels Quality level (QL) Consequence class Description C o n t r o l o r g a n i s m f o r s p e c i f i c a t i o n o f r e q u i r e m e n t s a n d c h e c k i n g QL3 CC3 Extensive quality level associated to extended measures for quality management, i
49、nspec- tion, and control Besides self-control and systematic control, independent party control shall also be executed: specification of requirements for quality management, assurance, and control, as well as the checking performed by an organisation different from that which has prepared the stage of the life cycle involved. Intens
