1、BSI Standards PublicationBS EN 16416:2013Geosynthetic clay barriers Determination of waterflux index Flexible wallpermeameter method atconstant headBS EN 16416:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 16416:2013.The UK participation in its preparatio
2、n was entrusted to TechnicalCommittee B/553, Geotextiles and geomembranes.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctappl
3、ication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 78120 9ICS 59.080.70; 91.100.50Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Stra
4、tegy Committee on 30 September 2013.Amendments issued since publicationDate Text affectedBS EN 16416:2013EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16416 September 2013 ICS 59.080.70; 91.100.50 English Version Geosynthetic clay barriers - Determination of water flux index - Flexible wall p
5、ermeameter method at constant head Barrires gosynthtiques argileuses - Dtermination de lindice eau par analyse en flux - Mthode au permamtre paroi flexible de charge constante Geosynthetische Tondichtungsbahnen - Bestimmung der Durchflussrate - Triaxialzellen-Methode mit konstanter Druckhhe This Eur
6、opean Standard was approved by CEN on 10 August 2013. 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 c
7、oncerning such national standards may be obtained on application to the CEN-CENELEC 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
8、 into its own language and notified to the CEN-CENELEC 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, Former Yugoslav Republic of Macedonia, Franc
9、e, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOM
10、ITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16416:2013: EBS EN 16416:2013EN 16416:2013 (E) 2 Contents Page Foreword 3 1 Scope 4 2 Normative r
11、eferences 4 3 Terms and definitions .4 4 Apparatus .4 5 Permeant water 8 6 Specimen sampling and preparation .8 7 Procedure .8 7.1 General 8 7.2 Head loss of apparatus .8 7.3 Specimen set-up 8 7.4 Consolidation and pressure hydration 9 7.5 Permeation .9 7.6 Termination Criteria .9 8 Calculation 9 9
12、Report 10 Annex A (informative) Hydraulic conductivity calculation. 11 Annex B (informative) Permittivity calculation (based on ASTM D 4491) 12 Bibliography . 13 BS EN 16416:2013EN 16416:2013 (E) 3 Foreword This document (EN 16416:2013) has been prepared by Technical Committee CEN/TC 189 “Geosynthet
13、ics”, 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 March 2014, and conflicting national standards shall be withdrawn at the latest by March 2014. Attent
14、ion 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. According to the CEN-CENELEC Internal Regulations, the national standards organisations of t
15、he following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Nether
16、lands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 16416:2013EN 16416:2013 (E) 4 1 Scope This European Standard describes an index test method that covers laboratory measurement of water flux through saturated clay geosynthe
17、tic barrier (GBR-C) specimens using a flexible wall permeameter at constant head. This test method is applicable to GBR-C products with no additional sealing layers attached. This test method provides a measurement of flux under a prescribed set of conditions that can be used for manufacturing quali
18、ty control. The test method can also be used to check conformance. The flux value determined using this test method is not considered to be representative of the in-service flux of a GBR-C. 2 Normative references The following documents, in whole or in part, are normatively referenced in this docume
19、nt and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 9862, Geosynthetics Sampling and preparation of test specimens (ISO 9862) ISO 554, Stan
20、dard atmospheres for conditioning and/or testing Specifications ISO 11465, Soil quality Determination of dry matter and water content on a mass basis Gravimetric method 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 flux volumetric flow rate
21、 per unit area normal to the plane of the product at a defined head SOURCE: EN ISO 10318, 4.3.3 4 Apparatus The apparatus shall consist of the following. 4.1 Constant head hydraulic system 4.1.1 General The system shall be capable of maintaining constant hydraulic pressures to within 2,5 % and shall
22、 include means to measure the hydraulic pressures to within the prescribed tolerance. In addition, the system shall be capable of maintaining a constant head loss across the test specimen to within 5 % and shall include means to measure the head loss with the same accuracy or better. BS EN 16416:201
23、3EN 16416:2013 (E) 5 4.1.2 System de-airing The hydraulic system shall be designed to facilitate rapid and complete removal of free air bubbles from flow lines. 4.1.3 Cell pressure system The hydraulic system shall have the capability to apply back pressure to the specimen to facilitate saturation.
24、The system shall be capable of maintaining the applied back pressure throughout the duration of the test. The cell pressure system shall be capable of applying, controlling, and measuring the back pressure to within 2,5 % of the applied pressure. The back pressure may be provided by a compressed gas
25、 supply, a deadweight acting on a piston, or any other method capable of applying and controlling the back pressure to the tolerance specified in this paragraph. NOTE Application of gas pressure directly to a liquid will dissolve gas in the liquid. A variety of techniques are available to minimise d
26、issolution of gas in the back pressure liquid, including separation of gas and liquid phases with a bladder and frequent replacement of the liquid with de-aired water. 4.2 Flow Measurement System 4.2.1 Accuracy of inflow and outflow Both inflow and outflow volumes shall be measured unless the lack o
27、f leakage, continuity of flow, and cessation of consolidation or swelling can be verified by other means. Required accuracy for the flow measured over an interval of time is 5 %. 4.2.2 De-airing and compliance of the system The flow-measurement system shall contain a minimum of dead space and be cap
28、able of complete and rapid de-airing. Rigid tubing shall be used so that volume change of the system in response to changes in pressure is minimised. 4.3 Permeameter cell pressure system The system for pressurising the permeameter cell shall be capable of applying and maintaining the cell pressure t
29、o within 2,5 % of the applied pressure. However, the effective stress on the test specimen shall be maintained to the desired value with an accuracy of 5 %. The device for pressurising the cell may consist of a reservoir connected to the permeameter cell and partially filled with de-aired water, wit
30、h the upper part of the reservoir connected to a compressed gas supply or other source of pressure (see NOTE). NOTE De-aired water is commonly used for the cell liquid to minimise potential for diffusion of air through the membrane into the specimen. Other liquids, such as oils, which have low gas s
31、olubilities, are also acceptable, provided they do not react with components of the permeameter and the flexible membrane. The use of a long (approximately 5 m to 7 m) tube connecting the pressurised cell liquid to the cell can help delay the appearance of air in the cell liquid and to reduce the fl
32、ux of dissolved air into the cell. 4.4 Permeameter Cell An apparatus shall be provided in which the specimen and porous end pieces, enclosed by a flexible membrane sealed to the cap and base, are subjected to controlled liquid pressures. A schematic diagram of a typical cell is shown in Figure 1. Th
33、e permeameter cell shall allow for observation of changes in height of the specimen, either by observation through the cell wall using a suitable instrument or by monitoring of either a loading piston or an extensometer extending through the top plate of the cell bearing on the top cap and attached
34、to a suitable measuring device. The piston or extensometer if used shall pass through a bushing and seal incorporated into the top plate and shall be loaded with sufficient force to compensate for the cell pressure acting over the cross-sectional area of the piston where it passes through the seal.
35、If deformations are measured, the deformation indicator BS EN 16416:2013EN 16416:2013 (E) 6 shall be graduated to 0,01 mm or better and shall have an adequate travel range. This piston or extensometer shall not restrict the swelling of the specimen. To facilitate gas removal, and thus saturation of
36、the hydraulic system, four drainage lines leading to the specimen, two each to the base and top cap, are recommended. The drainage lines shall be controlled by no-volume-change valves, such as ball valves, and shall be designed to minimise dead space in the lines. 4.5 Top cap and base An impermeable
37、, rigid top cap and base shall be used to support the specimen and provide for transmission of permeant liquid to and from the specimen. The base shall prevent leakage, lateral motion, or tilting, and the top cap shall be designed to receive the piston or extensometer, if used, such that the piston-
38、to-top cap contact area is concentric with the cap. The surface of the base and top cap that contacts the membrane to form a seal shall be smooth and free of scratches. Key 1 permeameter cell 2 porous end pieces 3 specimen 4 rubber O-rings 5 filter paper 6 back pressure system 7 outflow volume measu
39、ring device 8 inflow volume measuring device 9 vent lines Figure 1 Permeameter cell and test set-up 4.6 Flexible membranes The flexible membrane used to encase the specimen shall provide reliable protection against leakage. The membrane shall be carefully inspected prior to use and if any flaws or p
40、inholes are evident, the membrane shall be discarded. To minimise restraint of the specimen, the diameter or width of the unstretched membrane shall be between 90 % and 95 % of that of the specimen. The membrane shall be sealed to each of the BS EN 16416:2013EN 16416:2013 (E) 7 specimen base and cap
41、 with two rubber O-rings for which the unstressed, inside diameter or width is less than 90 % of the diameter or width of the base and cap, or by any other method that will produce an adequate seal. NOTE If necessary, membranes can be tested for flaws by placing them around a form sealed at both end
42、s with rubber O-rings, subjecting them to a small air pressure on the inside, and then dipping them into water. If air bubbles come up from any point on the membrane, or if any visible flaws are observed, the membrane is not suitable for use in the test. 4.7 Porous end pieces The porous end pieces s
43、hall be of material that is not attacked by the specimen or permeant liquid. The end pieces shall have plane and smooth surfaces and be free of cracks, chips, and non-uniformities. They shall be checked regularly to ensure that they are not clogged. The porous end pieces shall have a diameter no gre
44、ater than (100 2) mm, and their thickness shall be sufficient to prevent breaking. The hydraulic conductivity of the porous end pieces shall be substantially greater than that of the specimen to be tested such that there is no significant impedance of flow. Including the porous end pieces in the pro
45、cedures described in 7.1 will ensure that no significant impedance occurs. 4.8 Filter paper To prevent intrusion of material into the pores of the porous end pieces, one or more sheets of filter paper shall be placed between the top and bottom porous end pieces and the specimen. The hydraulic conduc
46、tivity of the filter paper shall be substantially greater than that of the specimen to be tested such that there is no significant impedance of flow. Including the filter paper in the procedures set forth in 7.1 will ensure that no significant impedance occurs. NOTE An appropriate type of filter pap
47、er is Whatman No. 1 (or equivalent).1)4.9 Devices for measuring the dimensions of the specimen Devices used to measure dimensions of the specimen other than the thickness shall be capable of measuring with an accuracy of 0,3 mm or better and shall be constructed such that their use will not disturb
48、the specimen. 4.10 Equipment for mounting the specimen Equipment for mounting the specimen in the permeameter cell shall include a membrane stretcher or cylinder and ring for expanding and placing O-rings on the base and top cap to seal the membrane. 4.11 Vacuum pump This pump assists with the de-ai
49、ring of the permeameter system and the saturation of the specimens. 4.12 Temperature maintaining device Testing shall be carried out at ambient temperature that shall not vary more than 3 C. This temperature shall be periodically measured and recorded, at a minimum, at the beginning of the permeation phase and at the end of the permeation phase of the test. 1) Whatman No.1 is an example of a suitable product available commercially. This information is given for the convenience of users of this European Standard and does not constitute a
