ISO INTERNATIONAL STANDARD 18674-2 First edition 2016-10-15 Geotechnical investigation and testing Geotechnical monitoring by field instrumentation - Part 2: Measurement of displacements along a line: Extensometers Reconnaissance et essais geotechniques - Mesures géotechniques - Partie 2: Mesure de deplacement le long d'une ligne par extensometre Reference number IS018674-2:2016(E) ISO @IS0 2016 IS0 18674-2:2016(E) COPYRIGHTPROTECTEDDOCUMENT @ IS0 2016, Published in Switzerland All rights reserved. Unless otherwise specified, 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 member body in the country of the requester. ISO copyright office Ch. de Blandonnet 8 . CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 [email protected] www.iso.org ii @IS02016-Allrightsreserved IS0 18674-2:2016(E) Contents Page Foreword .iv 1 Scope 1 2 Normative references 1 3 Terms and definitions 1 4 Symbols. .3 .4 5 Instruments 5.1 General 4 5.2 In-place extensometer 8 5.2.1 Measuring points. 8 5.2.2 Connecting elements 8 5.2.3 Measuring head and read-out device 9 5.3 Probe extensometer 10 5.3.1 Measuring points and guide tube. 10 5.3.2 Probe 11 5.5 Tape extensometer (convergence tape) 12 5.6 Measuring range and accuracy 12 6 Installation and measuring procedures 13 6.1 Installation. 13 6.1.1 Surface components. 13 6.1.2 Installation in boreholes and in fill 13 6.1.3 In-place extensometer 14 6.1.4 Probe extensometer. 14 6.1.5 Tape extensometer. 15 6.2 Carrying out the measurement. 15 6.2.1 Instrumentation check and calibration .15 6.2.2 Measurement .15 .15 7 Data processing and evaluation. 8 Reporting. .16 8.1 Installation report .16 8.2 Monitoring report. .16 Annex A (normative) Measuring and evaluation procedure .17 .26 AnnexB (informative)Backfillmaterials Annex C (informative) Geo-engineering applications .27 Annex D (informative) Measuring examples 28 Bibliography 46 IS02016-All rightsreserved ii