ISO INTERNATIONAL STANDARD 11058 Third edition 2019-05 Geotextiles and geotextile-related products Determination of water permeability characteristics normal to the plane, without load Géotextilesetproduitsapparentés-Déterminationdes caracteristiques de perméabilité a I'eau normalement au plan, sans contraintemecanique Referencenumber IS011058:2019(E) ISO @IS02019 IS011058:2019(E) COPYRIGHTPROTECTEDDOCUMENT @ISO2019 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either IsO at the address below orIso's memberbody in the countryof therequester. ISO copyright office CP 401 : Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone:+41227490111 Fax:+41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ii @ IS0 2019- All rights reserved IS011058:2019(E) Contents Page Foreword ..iv 1 Scope. .1 2 Normativereferences 3 Terms and definitions 4 Test specimens. .1 4.1 Handling. .1 4.2 Selection. ..1 4.3 Numberanddimensions .2 4.4 Specimen conditions 2 5 Constanthead method .2 5.1 Principle 2 5.2 Apparatus 2 5.3 Procedure .3 5.4 Calculation and expression ofresults .4 6 Falling head method .4 6.1 Principle.. 4 6.2 Apparatus. .5 6.3 Procedure .6 6.4 Calculationandexpressionofresults. .6 7 Test report .7 Annex A (informative) Determination of the correction factor, Rr, to a water temperature of 20°C. .11 AnnexB (normative)Relationshipbetweenhead lossandflowvelocity ..13 AnnexC (informative)Individualvelocityindexvaluesforahead lossof50mm ..15 AnnexD (informative) Experimental dataand calculations .16 @IS0 2019 -All rights reserved iii