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1、DRAFT FOR DEVELOPMENT DD CEN/TS 14418:2005 Geosynthetic barriers Test method for the determination of the influence of freezing- thawing cycles on the permeability of clay geosynthetic barriers ICS 59.080.70 ? Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:2
2、6:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD CEN/TS 14418:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 June 2006 BSI 2006 ISBN 0 580 47096 2 National foreword This Draft for Development is the official English language versio
3、n of CEN/TS 14418:2005. The UK participation in its preparation was entrusted to Technical Committee B/553, Geosynthetics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or propos
4、als for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement internation
5、al or European publications referred to in this 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
6、 include all the necessary provisions of a contract. Users are responsible for its correct application. This publication is not to be regarded as a British Standard. It is being issued in the Draft for Development series of publications and is of a provisional nature becuase the experts could not re
7、ach consensus at this stage. It should be applied on this provisional basis, so that information and experience of its practical application may be obtained. The BSI Committee, B/553, Geosynthetics, responding to CEN/TC 189, has repeatedly requested the data validating this Draft for Development. To
8、 date, no information has been submitted to CEN/TC 1890 and therefore, Committee B/553 has no alternative but to express at a national level, its serious concern at the technical validity of the proposed test procedure. Comments arising from the use of this Draft for Development are requested so tha
9、t UK experience can be reported to the European organization responsible for its conversion to a European standard. A review of this publication will be initiated 2 years after its publication by the European organization so that a decision can be taken on its status at the end of its 3-year life. N
10、otification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards. According to the replies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into a European Standard, to exte
11、nd the life of the Technical Specification or to withdraw it. Comments should be sent in writing to the Secretary of BSI Technical Committee B/553, Geosynthetics, at British Standards House, 389 Chiswick High Road, London W4 4AL, giving the document reference and clause number and proposing, where p
12、ossible, an appropriate revision of the text. Summary of pages This document comprises a front cover, an inside front cover, the CEN/TS title page, pages 2 to 12, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. A
13、mendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:26:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI TECHNICAL SPECIFICATION SPCIFICATION TECHNIQUE TECHNISCHE SPEZIFIKATION CEN/TS 14418 December 2005 ICS 59
14、.080.70 English Version Geosynthetic barriers - Test method for the determination of the influence of freezing-thawing cycles on the permeability of clay geosynthetic barriers Barrires gosynthtiques - Mthode dessai pour la dtermination de linfluence de cycles de gele-dgel sur la permabilit leau des
15、barrires gosynthtiques bentonitiques Geosynthetische Dichtungsbahnen - Prfverfahren zur Bestimmung des Einflusses von Frost-Tau- Wechselbeanspruchungen auf die Durchlssigkeit von geosynthetischen Tondichtungsbahnen This Technical Specification (CEN/TS) was approved by CEN on 3 April 2005 for provisi
16、onal application. The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard. CEN members are required to announce
17、the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS) until the final decision about the possible conversion of the CE
18、N/TS into an EN is reached. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia
19、, 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 2005 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN nati
20、onal Members. Ref. No. CEN/TS 14418:2005: E Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:26:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14418:2005 Contents Page Foreword3 Introduction.4 1 Scope5 2 Normative references5 3 Terms and definitions .5 4
21、 Principle5 5 Reagent.5 6 Apparatus.6 7 Procedure.8 8 Calculation and expression of results 10 9 Test report. 11 Bibliography. 12 2 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:26:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14418:2005 Foreword Thi
22、s Technical Specification (CEN/TS 14418:2005) has been prepared by Technical Committee CEN/TC 189 “Geosynthetics”, the secretariat of which is held by IBN/BIN. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to announce thi
23、s CEN Technical Specification: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdo
24、m. 3 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:26:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14418:2005 Introduction This Technical Specification defines a method for testing the influence of freezing-thawing cycles on the permeability of clay
25、 geosynthetic barriers. Such resistance is a requirement for many uses of these products. The influence ratio is an indication of the behaviour of the product when exposed to repeated freezing and thawing cycles in earth constructions. The permeability of saturated clay geosynthetic barriers may inc
26、rease in consequence of repeated freezing-thawing cycles. This Technical Specification does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and determine the
27、 applicability of regulatory limitations prior to use. The current Technical Specification has not yet been widely validated. The organisation of interlaboratory- tests to acquire more experience is recommended. 4 Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12
28、05:26:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14418:2005 1 Scope This Technical Specification specifies an index test to determine the influence ratio of freezing-thawing cycles on the flux through saturated clay geosynthetic barriers. This test is applicable to clay geosynthetic barrie
29、r products with a geotextile backing. It is not necessarily applicable to clay geosynthetic barrier products with a geomembrane backing. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited appl
30、ies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 10320, Geotextiles and geotextile-related products Identification on site (ISO 10320:1999) EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:1
31、987) 3 Terms and definitions For the purposes of this Technical Specification, the following term and definition applies. 3.1 influence ratio ratio of the flux value of a specimen exposed to wetting-drying cycles and divided by the flux through an unexposed reference specimen, expressed in percent 4
32、 Principle The flux through 100 mm diameter clay geosynthetic barrier specimens is determined with a flexible wall permeameter both on specimens exposed to freezing-thawing cycles and on unexposed reference specimens. Geosynthetic clay barrier samples of 300 mm x 300 mm are saturated under a pressur
33、e of (4 0,2) kPa for 48 h at constant room temperature. After saturation, one sample is stored in the freezer at 5 C for 24 h, while the reference sample remains at normal room temperature. After the freezing period the first sample is allowed to thaw at room temperature for 24 h. Then the samples a
34、re submerged again for 24 h at room temperature. This freezing-thawing cycle is performed four times before cutting the test specimens. The specimen is mounted in a flexible-wall permeameter, subjected to a cell pressure of 550 kPa and a back pressure of 515 kPa for a period of 48 h. Flow is initiat
35、ed using deionized water by raising the pressure on the inlet side of the test specimen to 530 kPa. The flux is determined when inflow and outflow are approximately equal (within 25 %). NOTE This test does not provide a hydraulic conductivity value. Hydraulic conductivity can be determined in a simi
36、lar way, but requires knowledge of the thickness of the specimen. This test does not include procedures for thickness measurement of the clay geosynthetic barrier or of its clay component. 5 Reagent De-aired, de-ionized water shall be in accordance with EN ISO 3696 grade 3. 5 Licensed Copy: London S
37、outh Bank University, London South Bank University, Tue Dec 12 05:26:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14418:2005 Water is used to permeate the test specimen and also to exert a back pressure on the test specimen. As the flux can be substantially influenced by the nature of the te
38、st liquid, de-aired, de-ionized water shall be used in this test method. The water shall be de-aired as well as de-ionized. The water is usually de-aired by boiling, by spraying a fine mist of water in a vessel connected to a vacuum source, or by forceful agitation of water in a container connected
39、to a vacuum source. The de-aired water shall not be exposed to air for prolonged periods to prevent the dissolving of air back into water. 6 Apparatus NOTE The apparatus used in this test method is commonly used to determine the hydraulic conductivity of soil specimens. However, flux values measured
40、 in this test are typically much lower than those commonly measured for natural soils. The leakage rate of the apparatus should be less than 10 % of the flux. 6.1 Hydraulic system The system shall be designed to facilitate rapid and complete removal of free air bubbles from flow lines and be capable
41、 of maintaining constant hydraulic pressures within 5 %. It may be one of the following types: method A: a constant head system, e.g. the system specified in ASTM D 5887:2003; provided it meets the criteria specified in this method; method B: a falling head method; method C: a constant rate of flow.
42、 Pressures shall be measured by any device of suitable accuracy, e.g. a pressure gage or an electronic pressure transducer. The hydraulic system shall be capable to apply and to maintain a backpressure within 5 % on the specimen, to facilitate saturation throughout the duration of the measurements.
43、The backpressure may be provided by a compressed gas supply, a dead-weight acting on a piston, or by any other suitable means. 6.2 Flow measurement system For the determination of flow volume within an accuracy of 5 %, a system shall be used with a graduated accumulator, a graduated pipette, a verti
44、cal standpipe in conjunction with an electronic pressure transducer or any other suitable device. Both inflow and outflow volumes shall be measured unless the absence of leakage, the continuity of the flow and the cessation of consolidation or swelling can be verified by other means. 6.3 Permeameter
45、 cell An apparatus shall be used in which the specimen and porous end pieces, enclosed by a flexible membrane sealed to the cap and base, are subjected to controlled fluid pressures. The permeameter cell may allow for observation of changes in height of the specimen, either by observation through th
46、e cell wall using a cathetometer or other instrument, or by monitoring of either a loading piston or an extensometer extending through the top plate bearing on the top cap and connected to the dial indicator or other measuring device. The piston or extensometer should pass through a bushing and seal
47、 incorporated into the 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. If deformations are measured, the 6 Licensed Copy: London South Bank University, London South Bank Universit
48、y, Tue Dec 12 05:26:01 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN/TS 14418:2005 deformation indicator shall be a dial indicator or cathetometer graduated to 0,3 mm or better and having an adequate travel range, or any other suitable measuring device of the same accuracy. 6.4 Impermeable rigid to
49、p cap and base This is intended to support the specimen, to provide for transmission of the permeant liquid and to form the specimen. The diameter or width of the top cap and the base shall be equal to the diameter of the specimen within 5 %. The base shall prevent leakage, lateral motion or tilting and the top cap shall be designed to receive the piston or extensometer if used, so that the contact area is concentric with the cap. The surface of base and top cap in