BS EN ISO 12958-2010 Geotextiles and geotextile-related products - Determination of water flow capacity in their plane《土工布及相关产品 其平面内的水流量的测定》.pdf

1、BS EN ISO12958:2010ICS 59.080.70NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDGeotextiles andgeotextile-relatedproducts Determination of waterflow capacity in theirplane (ISO 12958:2010)This British Standardwas published under theauthority of the StandardsPoli

2、cy and StrategyCommittee on 31 May 2010 BSI 2010ISBN 978 0 580 68000 7Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 12958:2010National forewordThis British Standard is the UK implementation of EN ISO 12958:2010.It supersedes BS EN ISO 12958:1999 which is withdrawn.The UK parti

3、cipation in its preparation was entrusted to TechnicalCommittee B/553, Geotextiles and geomembranes.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are respo

4、nsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 12958 April 2010 ICS 59.080.70 Supersedes EN ISO 12958:1999English Version Geotextiles and geotextile-related products - Determi

5、nation of water flow capacity in their plane (ISO 12958:2010) Gotextiles et produits apparents - Dtermination de la capacit de dbit dans leur plan (ISO 12958:2010) Geotextilien und geotextilverwandte Produkte - Bestimmung des Wasserableitvermgens in der Ebene (ISO 12958:2010) This European Standard

6、was approved by CEN on 8 March 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such na

7、tional standards may be obtained on application to the CEN Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language an

8、d notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,

9、 Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2010 CEN Al

10、l rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 12958:2010: EBS EN ISO 12958:2010EN ISO 12958:2010 (E) 3 Foreword This document (EN ISO 12958:2010) has been prepared by Technical Committee ISO/TC 221 “Geosynthetics“ in collaboration

11、with Technical Committee CEN/TC 189 “Geosynthetics” the secretariat of which is held by NBN. 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 October 2010, and conflicting national standards shall

12、be withdrawn at the latest by October 2010. 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 document supersedes EN ISO 12958:1999

13、. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Irela

14、nd, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 12958:2010 has been approved by CEN as a EN ISO 12958:2010 without any modification. BS EN ISO 12

15、958:2010ISO 12958:2010(E) ISO 2010 All rights reserved iiiContents Page Foreword iv 1 Scope1 2 Normative references1 3 Terms and definitions .1 4 Principle2 5 Apparatus and materials.2 6 Specimens5 6.1 Handling .5 6.2 Selection.5 6.3 Number and dimensions.5 6.4 Specimen condition 6 7 Test procedure.

16、6 8 Calculations and expression of results 7 9 Test report8 Annex A (informative) Determination of the correction factor RTfor conversion to a water temperature of 20 C .10 Annex B (informative) Experimental data and calculations for a specimen.12 Bibliography13 BS EN ISO 12958:2010ISO 12958:2010(E)

17、 iv ISO 2010 All rights reservedForeword 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 inter

18、ested 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 Electrotechnical

19、 Commission (IEC) on all matters of electrotechnical 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 te

20、chnical committees are circulated to the 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. IS

21、O shall not be held responsible for identifying any or all such patent rights. ISO 12958 was prepared by Technical Committee ISO/TC 221, Geosynthetics. This second edition cancels and replaces the first edition (ISO 12958:1999), which has been technically revised. BS EN ISO 12958:2010INTERNATIONAL S

22、TANDARD ISO 12958:2010(E) ISO 2010 All rights reserved 1Geotextiles and geotextile-related products Determination of water flow capacity in their plane 1 Scope This International Standard specifies a method for determining the constant-head water flow capacity within the plane of a geotextile or geo

23、textile-related product. NOTE 1 If the full water flow capacity characteristics of the geotextile or geotextile-related product have previously been established, then for control purposes it can be sufficient to determine the water flow capacity at two loads and both gradients. NOTE 2 The compressib

24、ility of the product over time will substantially influence the in-plane water flow capacity. Test methods for assessing the compressive creep behaviour of geotextiles or geotextile-related products are described in ISO 25619-1. The test report is judged in conjunction with the long-term compressive

25、 creep behaviour in order to assess the long-term flow capacity. 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 docume

26、nt (including any amendments) applies. ISO 2854, Statistical interpretation of data Techniques of estimation and tests relating to means and variances ISO 5813, Water quality Determination of dissolved oxygen Iodometric method ISO 9862, Geosynthetics Sampling and preparation of test specimens ISO 98

27、63-1, Geosynthetics Determination of thickness at specified pressures Part 1: Single layers ISO 10320, Geotextiles and geotextile-related products Identification on site 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 normal compressive stres

28、s compressive stress components normal to the plane of the geotextile or geotextile-related product NOTE The normal compressive stress is expressed in kilopascals. 3.2 in-plane flow fluid flow within the geotextile or geotextile-related product and parallel to its plane BS EN ISO 12958:2010ISO 12958

29、:2010(E) 2 ISO 2010 All rights reserved3.3 in-plane water flow capacity volumetric flow rate of water per unit width of specimen at a defined gradient and load NOTE The term transmissivity is related to laminar flow conditions only and equals the water flow capacity at a hydraulic gradient equal to

30、unity. As non-laminar flow may occur, the term water flow capacity is preferred. 3.4 hydraulic gradient ratio of the head loss in the geotextile or geotextile-related product specimen to the distance between the measuring points 4 Principle The flow of water within the plane of a geotextile or geote

31、xtile-related product is measured under varying normal compressive stresses, with typical hydraulic gradients and with defined contact surfaces. 5 Apparatus and materials 5.1 Constant-head in-plane water flow apparatus, satisfying the following requirements: a) The apparatus shall be capable of main

32、taining a constant head loss at different water levels, at least those corresponding to hydraulic gradients of 0,1 and 1,0, while maintaining a water head at the point of discharge of not greater than 100 mm. b) If the water head exceeds 100 mm, the normal stress shall be corrected for the excess. c

33、) The apparatus shall be capable of maintaining the proposed normal compressive stress on the specimen without any deformation which would influence the test results. d) The apparatus shall include a loading mechanism capable of exerting a constant normal compressive stress on the geotextile specime

34、n to an accuracy of 5 %. e) The surfaces contacting the specimen shall be closed-cell foam rubber whose properties satisfy the compression-deflection envelope, illustrated in Figure 1, when tested in accordance with ISO 9863-1. For specimens with a thickness up to 10 mm, foam rubber with a nominal t

35、hickness of 10 mm shall be used on each face. For specimens with a thickness between 10 mm and 25 mm, foam rubber with a nominal thickness of 1 to 1,25 times the specimen thickness shall be used on each face. For specimens with a thickness over 25 mm, the foam rubber on each face shall have a nomina

36、l thickness of 25 mm. Two layers of foam rubber may be combined to achieve the desired thickness. The width of the foam shall be the same as that of the loading platen. The length of the foam should normally be the same as the loading platen. However, to avoid obstruction at both the inlet and outle

37、t due to compression of the foam, it is recommended that its length be reduced, where necessary, by 0,4 times its nominal thickness. When the geotextile-related products to be tested have been designed to perform their hydraulic functions against rigid boundaries, the foam rubber membranes shall not

38、 be used, but shall be replaced by the appropriate boundary, e.g. a stiff high-density polyethylene liner or a concrete panel. Products for such applications can be identified typically by the fact that they have no geotextile layers to prevent soil intrusion and in fact are not placed directly agai

39、nst a soil boundary. When foam rubber layers have not been used, the test report shall include the specific boundary used. BS EN ISO 12958:2010ISO 12958:2010(E) ISO 2010 All rights reserved 3Key X normal compressive stress, in kilopascals Y thickness reduction, in percent Figure 1 Compression-deflec

40、tion envelope of an elastomeric closed-cell foam rubber f) The apparatus shall have a minimum width of 0,2 m and a minimum net hydraulic length of 0,3 m. It shall be capable of testing specimens up to a thickness of 50 mm. It shall also be capable of accepting foam rubber with a thickness of 25 mm i

41、n contact with both faces of the material to be tested. g) The apparatus shall be essentially leaktight. At the lowest normal compressive stress and the highest hydraulic gradient, when the platen or pressure membranes with the contact surfaces are seated in the unit without the test specimen, the l

42、eakage shall not exceed 0,2 ml/s. Some examples of apparatus are shown in Figure 2. For determination of the hydraulic head loss, it is recommended that the apparatus in Figures 2 b) and 2 c) be provided with two manometers at a spacing of at least 0,3 m within the specimen. For very low flows, the

43、leakage shall not exceed 10 % of the flow value. BS EN ISO 12958:2010ISO 12958:2010(E) 4 ISO 2010 All rights reservedDimensions in millimetres a) b) c) Key 1 water supply 5 membrane 9 loading platen 2 water collection 6 pressure cell 10 overflow weirs at hydraulic gradients 0,1 and 1,0 3 manometers

44、7 foam 11 water reservoir 4 specimen 8 load 12 base Figure 2 Typical examples of apparatus BS EN ISO 12958:2010ISO 12958:2010(E) ISO 2010 All rights reserved 55.2 Water: For water flow rates up to 0,3 l/(ms), the water used shall be de-aerated or fed from a stilling tank. The water shall be at a tem

45、perature between 18 C and 22 C and the water temperature should preferably be at or above the ambient temperature of the test laboratory. The water shall not be continuously recycled. The oxygen content shall not exceed 10 mg/kg, when measured at the point where the water enters the apparatus. For w

46、ater flow rates greater than 0,3 l/(ms), water from the mains supply may be used. The temperature shall be noted and all necessary measures shall be taken to avoid the inclusion of air in the tap water. NOTE As temperature correction relates only to laminar flow, it is advisable, should the flow be

47、non-laminar, to work at temperatures as close as possible to 20 C to minimize inaccuracies associated with inappropriate correction factors. The water shall be filtered if suspended solids are visible to the naked eye or if solids accumulate on or in the specimen, thus inhibiting flow. 5.3 Dissolved

48、-oxygen meter, or apparatus in accordance with ISO 5813. 5.4 Stopwatch, accurate to 0,1 s. 5.5 Thermometer, accurate to 0,5 C. 5.6 Equipment for determining the water flow rate: When the water flow rate is determined by measurements of volume, a measuring vessel for determining the volume to an accu

49、racy of 1 % is required. When the water flow rate is measured directly by a gauge, it shall be measurable to an accuracy of 5 %. When the volume is determined by weighing, it shall be determined to an accuracy of 1 %. 5.7 Measuring device for determining the applied head to an accuracy of 1 mm. 5.8 Measuring device for determining the applied normal stress to an accuracy of 1 %. 6 Specimens 6.1 Handling In order to prevent disturbing its structure, the sample shall be handled as infrequently as possible and shall not be f