1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58pipelines ICS 23.040.10Earthquake- and subsidence-resistant design of ductile iron BRITISH STANDARD
2、BS ISO 16134:2006BS ISO 16134:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 27 February 2006 BSI 27 February 2006ISBN 0 580 47856 4Cross-referencesThe British Standards which implement international publications referred to in this docu
3、ment 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.
4、Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 32, an inside back
5、 cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this committee can be obtained on request to its secretary.enquiries on the interpre
6、tation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard reproduces verbatim ISO 16134:2006 and implements it as the UK national standard.The UK participation in its p
7、reparation was entrusted to Technical Committee PSE/10, Iron pipes and fittings, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any Reference numberISO 16134:2006(E)INTERNATIONAL STANDARD ISO16134First edition2006-02
8、-01Earthquake- and subsidence-resistant design of ductile iron pipelines Conception de canalisations en fonte ductile rsistant aux tremblements de terre et aux affaissements BS ISO 16134:2006ii iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Terms and definitions. 1 3 Earthquake-resistant
9、design . 1 3.1 Seismic hazards to buried pipelines. 1 3.2 Qualitative design considerations 2 3.3 Design procedure . 2 3.4 Earthquake resistance calculations and safety checking 3 3.5 Calculation of earthquake resistance Response displacement method 3 4 Design for ground deformation by earthquake .
10、6 4.1 General. 6 4.2 Evaluation of possibility of liquefaction. 6 4.3 Checking basic resistance. 7 5 Design for ground subsidence in soft ground (e.g. reclaimed ground) . 7 5.1 Calculating ground subsidence 7 5.2 Basic safety checking 7 6 Pipeline system design 8 6.1 Pipeline components 8 6.2 Earthq
11、uake-resistant joints . 8 Annex A (informative) Example of earthquake resistance calculation. 9 Annex B (informative) Relationship between seismic intensity scales and ground surface acceleration . 17 Annex C (informative) Example of calculation of liquefaction resistance coefficient value 18 Annex
12、D (informative) Checking pipeline resistance to ground deformation 23 Annex E (informative) Example of ground subsidence calculation 26 Bibliography . 32 BS ISO 16134:2006iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
13、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, govern
14、mental 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 Di
15、rectives, 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 b
16、odies 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 16134 was prepared by Technical Committee ISO/TC 5, Ferrous metal pipes and
17、 metallic fittings, Subcommittee SC 2, Cast iron pipes, fittings and their joints. BS ISO 16134:2006vIntroduction Buried pipelines are often subjected to damage by earthquakes. It is therefore necessary to take earthquake resistance into consideration, where applicable, in the design of the pipeline
18、s. In reclaimed ground and other areas where ground subsidence is expected, the pipeline design must also take the subsidence into consideration. Even though ductile iron pipelines are generally considered to be earthquake-resistant, since their joints are flexible and expand/contract according to t
19、he seismic motion to minimize the stress on the pipe body, nevertheless there have been reports of the joints becoming disconnected by either a large quake motion or major ground deformation such as liquefaction. BS ISO 16134:2006blank1Earthquake- and subsidence-resistant design of ductile iron pipe
20、lines 1 Scope This International Standard specifies the design of earthquake- and subsidence-resistant ductile iron pipelines suitable for use in areas where seismic activity and land subsidence can be expected. It provides a means of determining and checking the resistance of buried pipelines and a
21、lso gives example calculations. It is applicable to ductile iron pipes and fittings with joints that have expansion/contraction and deflection capabilities, used in pipelines buried underground. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1
22、 burying placing of pipes underground in a condition where they touch the soil directly 2.2 response displacement method earthquake-resistant calculation method in which the underground pipeline structure is affected by the ground displacement in its axial direction during an earthquake 2.3 liquefac
23、tion phenomenon in which sandy ground rapidly loses its strength and rigidity due to repeated stress during an earthquake, and where the whole ground behaves just like a liquid 2.4 earthquake-resistant joint joint having slip-out resistance as well as expansion/contraction and deflection capabilitie
24、s 3 Earthquake-resistant design 3.1 Seismic hazards to buried pipelines In general, there are several main causes of seismic hazards to buried pipelines: a) ground displacement and ground strain caused by seismic ground shaking; b) ground deformation such as a ground surface crack, ground subsidence
25、 and lateral spread induced by liquefaction; c) relative displacement at the connecting part with the structure, etc.; d) ground displacement and rupture along a fault zone. Since ductile iron pipe has high tensile strength as well as the capacity for expansion/contraction and deflection from its jo
26、int part, giving it the ability to follow the ground movement during the earthquake, the BS ISO 16134:20062 stress generated on the pipe body is relatively small. Few ruptures of pipe body have occurred during earthquakes in the past. It is therefore important to consider whether the pipeline can fo
27、llow the ground displacement and ground strain without slipping out of joint when considering its earthquake resistance. The internal hydrodynamic surge pressures induced by seismic shaking are normally small enough not to be considered. 3.2 Qualitative design considerations 3.2.1 General To increas
28、e the resistance of ductile iron pipelines to seismic hazards, the following qualitative design measures should be taken into consideration. a) Provide pipelines with expansion/contraction and deflection capability. EXAMPLE Use of shorter pipe segments, special joints or sleeves and anti-slip-out me
29、chanisms according to the anticipated intensity or nature of the earthquake. b) Lay pipelines in a firm foundation. c) Use smooth back fill materials. NOTE Polyethylene sleeves and special coating are also effective in special cases. d) Install more valves. 3.2.2 Where high earthquake resistance is
30、needed It is desirable to enhance the earthquake resistance of parts connecting the pipelines to structures and when burying the pipes in a) soft ground such as alluvium, b) reclaimed ground, c) filled ground, d) suddenly changing soil types (geology) or topography, e) sloping ground, f) near revetm
31、ents, g) liquefied ground, and/or h) near an active fault. 3.3 Design procedure To ensure earthquake-resistant design for ductile iron pipelines: a) select the piping route; b) investigate the potential for earthquakes and ground movement; c) assume probable earthquake motion (seismic intensity); d)
32、 undertake earthquake-resistant calculation and safety checking; e) select joints. Solid/firm foundations should be chosen for the pipeline route. When investigating earthquakes and ground conditions, take into account any previous earthquakes in the area where the pipeline is to be laid. BS ISO 161
33、34:200633.4 Earthquake resistance calculations and safety checking When checking the resistance of pipelines to the effects of earthquakes, the calculation shall be carried out for the condition in which the normal load (dead load and normal live load) is combined with the influence of the earthquak
34、e. The pipe body stress, expansion/contraction value of joint, and deflection angle of joint are calculated by the response displacement method. Earthquake resistance is checked by comparing these values with their respective allowable values. The basic criteria are given in Table 1. A flowchart of
35、earthquake resistance determination and safety checking is shown in Figure 1. The basic equations only for earthquake resistance calculation are given in 3.5. A detailed example of calculation is given in Annex A. Table 1 Basic earthquake resistance check criteria Load condition Criterion Pipe body
36、stress u Allowable stress (proof stress) of ductile iron pipeExpansion/contraction value of jointu Allowable expansion/contraction value of ductile iron pipe joint Load in earthquake motion and normal load Deflection angle of joint u Allowable deflection angle of ductile iron pipe joint 3.5 Calculat
37、ion of earthquake resistance Response displacement method 3.5.1 General This method shall be used except when the manufacturer and the customer agree on an alternative recognized method. 3.5.2 Design earthquake motion The design acceleration for different seismic intensity scales can be determined a
38、ccording to the relationship between the several kinds of seismic intensity scales and the acceleration of ground surface, as given in Annex B. 3.5.3 Horizontal displacement amplitude of ground The horizontal displacement amplitude of the ground is calculated using Equation (1) (see Annex A): ()2Ghc
39、os22T xUx aH =(1) where ( )hUx is the horizontal displacement amplitude of the ground x m deep from the ground surface to the centre line of the pipe, in metres (m); x is the depth from the ground surface, in metres (m); TGis the predominant period of the subsurface layer, in seconds (s); a is the a
40、cceleration on the ground surface for design, in metres per second squared (m/s2); H is the thickness of the subsurface layer, in metres (m). BS ISO 16134:20064 Figure 1 Flowchart for calculation of earthquake resistance of buried pipelines BS ISO 16134:200653.5.4 Pipe body stress Pipe body stress i
41、s calculated using Equations (2), (3) and (4). Axial stress: ( )hL11UxEL= (2) Bending stress: ()2hB2222 DU xEL = (3) Combined stress: 22LB3,12x=+ (4) where L , B are the axial stress and the bending stress, respectively, in pascals (Pa); x is the combination of the axial and bending stresses, in pas
42、cals (Pa); 1 is the correction factor of axial stress in the case of expansion flexible joints; 2 is the correction factor of the bending stress in the case of expansion flexible joints; 1 , 2 are the transfer coefficient of ground displacement in the pipe axis and pipe perpendicular directions, res
43、pectively; ( )hUx is the horizontal displacement amplitude of ground x m deep from the ground surface, in metres (m); L is the wavelength, in metres (m); D is the outside diameter of the buried pipeline, in metres (m); E is the elastic modulus of the buried pipeline, in pascals (Pa). 3.5.5 Expansion
44、/contraction of joint in pipe axis direction The amount of expansion/contraction of the joint in the pipe axis direction is calculated using Equation (5) (see Annex A): Gul= (5) where u is the amount of expansion/contraction of the joint in the pipe axis direction, in metres (m); Gis the ground stra
45、in UL=hL is the wavelength, in metres (m); Uh is the horizontal displacement amplitude of ground x m deep from the ground surface, in metres (m); l is the pipe length, in metres (m). BS ISO 16134:20066 3.5.6 Joint deflection angle The joint deflection angle is calculated using Equation (6) (see Anne
46、x A): 2h24 lUL = (6) where is the joint deflection angle, in radians (rad); l is the pipe length, in metres (m); Uhis the horizontal displacement amplitude of ground x m deep from the ground surface, in metres (m); L is the wavelength, in metres (m). The above calculations, such as the amount of exp
47、ansion/contraction of joint by the response displacement method, are based on the assumption that the ground will deform uniformly. However, since strain can be concentrated locally during an earthquake (due to the heterogeneity of the ground) and there is a possibility that the value can be greater
48、 than the calculation result, a certain value of safety margin for instance, twice as much is recommended. 4 Design for ground deformation by earthquake 4.1 General Large-scale ground deformation such as ground cracks, ground subsidence and lateral displacement near revetments and inclined ground ca
49、n be generated by liquefaction during an earthquake. Since such ground deformations can affect the buried pipeline, it is necessary to consider this possibility and to take it into account in the pipeline design. 4.2 Evaluation of possibility of liquefaction The possibility of liquefaction shall be evaluated for soil layers when the following conditions are present: a) saturated soil layer u 25 m from the ground surface; b) average grain diameter, D50, u 10 mm; c) content by weight
