1、BRITISH STANDARD BS EN ISO 13426-1:2003 Geotextiles and geotextile-related products Strength of internal structural junctions Part 1: Geocells The European Standard EN ISO 13426-1:2003 has the status of a British Standard ICS 59.080.70 BS EN ISO 13426-1:2003 This British Standard was published under
2、 the authority of the Standards Policy and Strategy Committee on 18 July 2003 BSI 18 July 2003 ISBN 0 580 42275 5 National foreword This British Standard is the official English language version of EN ISO 13426-1:2003. It is identical with ISO 13426-1:2003. The UK participation in its preparation wa
3、s entrusted to Technical Committee B/553, Geosynthetics, which has the responsibility to: 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 th
4、is 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 co
5、ntract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals
6、 for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, pages 2 to 16, an inside back cover and a back cover. The BSI
7、copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 13426-1 January 2003 ICS 59.080.70 English version Geotextiles and geotextile-related products -
8、 Strength of internal structural junctions - Part 1: Geocells (ISO 13426-1:2003) Gotextiles et produits apparents - Rsistance des liaisons de structures internes - Partie 1: Gosynthtiques alvolaires (ISO 13426-1:2003) Geotextilien und geotextilverwandte Produkte - Festigkeit produktinterner Verbindu
9、ngen - Teil 1: Geozellen (ISO 13426-1:2003) This European Standard was approved by CEN on 1 August 2002. 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
10、. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the 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 u
11、nder the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, I
12、taly, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2003 CEN All rights of exploita
13、tion in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 13426-1:2003 EEN ISO 13426-1:2003 (E) 2 Contents page Foreword3 Introduction .3 1 Scope 3 2 Normative references4 3 Terms and definitions .4 4 Principle4 4.1 Method A: Tensile shear test (Figure 1)5 4.2 Me
14、thod B: Peeling test (Figure 2) .5 4.3 Method C: Splitting test (Figure 3) 5 4.4 Method D: Local overstressing test (Figure 4) 5 5 Conditioning of specimens 5 6 Test specimens6 7 Apparatus.6 7.1 Tensile testing machine 6 7.2 Clamps 6 8 Test procedure.6 9 Calculations .7 9.1 General7 9.2 Method A: Te
15、nsile shear .7 9.3 Method B: Peeling.7 9.4 Method C: Splitting7 9.5 Method D: Local overstressing8 10 Test report 8EN ISO 13426-1:2003 (E) 3 Foreword This document (EN ISO 13426-1:2003) has been prepared by Technical Committee CEN/TC 189 “Geosynthetics“, the secretariat of which is held by IBN, in c
16、ollaboration with Technical Committee ISO/TC 221 “Geosynthetics“. 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 July 2003, and conflicting national standards shall be withdrawn at the latest by
17、July 2003. 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, Hungary, Iceland, Ireland, Italy, Luxembourg, Malt
18、a, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Introduction Geocells are geotextile-related products composed of single strips interconnected in several possible ways (extrusion, thermal bonding, gluing, hot melt, stitching, etc) to form a panel of adj
19、acent cells, where generally the contact between two elements occurs along lines or in specific points, and not uniformly on the whole surface. These lines or points are referred to as “junctions“. A geocell junction may fail in four different ways: 1) by shear (see Figure 1): when failure is caused
20、 by a force parallel to the junction itself; 2) by peeling or delamination (see Figure 2): when failure is caused by a force, normal to the junction, which separates the cells from each other at one edge of the junction; 3) by tensile stress (see Figure 3): when a force, normal to the junction, pull
21、s away the two cells adjacent to the junction; 4) by local overstressing (see e.g. Figure 4: geocells secured with pins) : when the fixation element locally overstresses the junction, leading to a compression, shear or peel failure. NOTE This can be considered as a performance property, in the same
22、way as a tensile test on seams/joints. It is therefore impossible to define one single testing method for measuring the junction strength of geocells. Hence this standard includes the principles for testing the four failure mechanisms explained above. These principles should be adapted to each singl
23、e product. In order to avoid confusion about the interpretation of figures, reference should be made to the exact test method in test reports and data sheets, e.g. EN ISO 13426-1, method A shear strength of internal structural junctions. 1 Scope This standard describes index test methods for the det
24、ermination of the strength of internal structural junctions of geocells under different loading conditions.EN ISO 13426-1:2003 (E) 4 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at t
25、he appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of th
26、e publication referred to applies (including amendments). EN 963, Geotextiles and geotextile-related products - Sampling and preparation of test specimens (ISO 9862:1990) EN ISO 7500-1, Metallic materials - Verification of static uniaxial testing machines - Part 1: Tension/compression testing machin
27、es (ISO 7500-1:1999) ISO 554, Standard atmospheres for conditioning and/or testing Specifications 3 Terms and definitions For the purposes of this European Standard, the following terms and definitions apply: 3.1 geocell three-dimensional, permeable, polymeric (synthetic or natural) honeycomb or web
28、 structure made of strips linked in a staggered pattern, used to hold soil particles, roots and small plants for erosion control and soil containment applications in civil engineering 3.2 junction point, line or area where two strips are connected to form the unit cells of a geocell structure 3.3 fa
29、stening system system (staples, pegs, U-shaped bars, etc.) used to fix the geocells to the ground at single points 3.4 nominal cell size length L c(in machine direction) and width W c(in cross-machine direction) of the cell when opened according to the specification 4 Principle Specimens of geocells
30、 are tested in accordance with one or more of the following four test methods representing different stress modes. NOTE 1 It is possible that, for some products, not all four test methods can be applied. NOTE 2 In order to perform the tests correctly, information about the nominal open cell sizes (L
31、c, Wc) and the direction of installation of the geocells panels, e.g. with the machine direction down the slope or parallel to the contour lines, should be provided.EN ISO 13426-1:2003 (E) 5 4.1 Method A: Tensile shear test (Figure 1) This test is performed on a X-shaped specimen cut from a geocell
32、panel. The junction forms the centre of the X. The left upper leg and the right lower leg of the X are trimmed close to the junction. The two remaining legs are mounted in the clamps of a tensile testing machine. The specimen is tested at constant rate of strain and the peak tensile shear resistance
33、 is measured and recorded. 4.2 Method B: Peeling test (Figure 2) This test is performed on a X-shaped specimen cut from a geocell panel. Both upper legs of the X are mounted in the clamps of a tensile testing machine and tested at constant rate of strain until peel failure of the junction occurs. Th
34、e peak peel resistance is measured and recorded. For products having a non-symmetric junction, the peel test shall be performed on the upper legs and on the lower legs. 4.3 Method C: Splitting test (Figure 3) This test is performed on a X-shaped specimen cut from a geocell panel. The left legs of th
35、e X are mounted in a special clamp keeping the edges of the legs apart at a specified distance. NOTE The right legs are mounted in a similar way. This simulates the aperture of the cells when installed with the machine direction parallel to the contour lines of the slope. The specimen shall be place
36、d in the clamps at the same cell aperture as indicated by the nominal cell size (L c , W c ). The specimen shall be mounted slightly in tension, i.e. without any slack. The two clamps are inserted in a tensile testing machine and tested at constant rate of strain until a tensile split failure of the
37、 junction occurs. The peak split resistance is measured and recorded. 4.4 Method D: Local overstressing test (Figure 4) This test is performed on a X-shaped specimen cut from the geocell panel, the upper and lower legs being oriented in the production direction. The upper legs of the X are mounted i
38、n a special clamp keeping the edges of the two legs apart at a specified distance. The lower legs are mounted in a similar way. NOTE This simulates the aperture of the cells when installed. The two clamps are mounted in a tensile testing machine. A steel rod or wooden peg, or any other means simulat
39、ing a real fastening system, is placed across and over the junction, and fixed to the base of the testing machine. The specimen is tested at a constant rate of strain until failure occurs due to plasticization of the junction by the fastening system. The maximum tensile strength is measured and reco
40、rded. When geocells are installed with the machine direction along the contour lines, the specimen shall be mounted in the clamps as shown in Figure 3. For products having a non-symmetric junction, this test shall be performed twice, i.e. by mounting the upper legs as well as the lower legs in the m
41、oving clamp. 5 Conditioning of specimens Test specimens shall be conditioned and the tests conducted in the standard atmosphere for testing, defined in ISO 554, i.e. at a temperature of (20 2) C and a relative humidity of (65 2) % NOTE Conditioning and/or testing at a specified relative humidity may
42、 be omitted if it can be shown that results are not affected.EN ISO 13426-1:2003 (E) 6 6 Test specimens Take specimens in accordance with EN 963. At least five specimens shall be tested for each of the relevant directions of the product. If junctions are not symmetrical, five specimens for each side
43、 of the junction shall be tested. Cut specimens according to the shapes and dimensions shown in Figures 5, 6, 7, and 8, respectively for the test methods A, B, C, D, described in 4.1 to 4.4. Cut specimens always such that clamping occurs at equal distance between junctions. 7 Apparatus 7.1 Tensile t
44、esting machine A constant rate of extension tensile testing machine, in accordance with EN ISO 7500-1, shall be used. 7.2 Clamps The clamps shall be sufficiently wide to hold the entire width of the specimen. They shall be equipped with appropriate means to prevent specimen slippage or damage. NOTE
45、Compressive jaws should be used for most products. 8 Test procedure All test methods are carried out at a constant rate of strain of 20 % per minute. Adjust the distance between the jaws at the start of the test to the required test specimen length 3 mm. Set the machine so as to induce the required
46、strain rate of 20% per minute. Mount the test specimen centrally in the jaws. Take care that the specimen length is parallel to the application direction of the force. Start the tensile machine and continue until specimen rupture occurs. Stop the machine, record and report the maximum load to an acc
47、uracy of 2 % of the full-scale reading. Report the related strain to the first decimal. Reset to the initial gauge position. The decision to discard a test result shall be based on observation of the specimen and on the inherent variability of the product. In the absence of other criteria for reject
48、ing a jaw break, any failure occurring within 5 mm of the jaws, which results in a value below 50 % of the average value of all other tests, shall be discarded. No other break results shall be discarded, unless the test is known to be invalid. NOTE 1 The precise reason of the specimens rupture in or
49、 near the jaws is not easy to determine. If a specimen is damaged by the jaws the test result should be discarded. If, however, it is merely due to randomly distributed weaknesses in the test specimen, the test result should be accepted. In some cases, it may also be caused by a concentration of stress in the area adjacent to the jaws because they prevent the test specimen from contracting laterally when the load is applied. In these cases, a rupture near the edge of the jaws i
