ISO INTERNATIONAL STANDARD 18407 First edition 2018-05 Simplified design of prestressed concrete tanks for potable water Conception simplifiée du réservoir pour I'eau potable en béton pré- armé Reference number IS0 18407:2018(E) so International Organization for Standardization Shenzhen Institute of Standards and Technology 9972181 @IS02018 IS0 18407:2018(E) COPYRIGHTPROTECTEDDOCUMENT @IS02018 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 internetoranintranet, without priorwrittenpermission.Permission canberequested from either Iso at the address below or Iso's member body in the country of the requester. ISO copyright office CP 40i: Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 01 11 Fax: +41 22 749 09 47 Email: copyright@iso.org Website: www.iso.org Published in Switzerland ganizationfor Standardization icensee-Shenzhen Institute of Standards andeclSogf1&-All rights reserved rious National Standards Bodies IS0 18407:2018(E) Contents Page Foreword ..vi Introduction. ..vii 1 Scope. 2 Normative references 3 Terms and definitions 4 Symbols. ..4 5 Design principles ..12 6 Load. .13 6.1 General. ..13 6.2 Deadweight .13 6.3 Imposed ioad .13 6.4 Hydrostatic water pressure ..14 6.5 Prestress .14 6.5.1 General. ..14 6.5.2 Prestressing force immediately after prestressing .14 6.5.3 Effective prestressing force.. .18 6.5.4 Indeterminateforcesduetoprestress ..19 6.6 Creep and drying shrinkage of concrete. .19 6.7 Effect of temperature .19 6.8 Seismic action 20 6.9 Wind load. 20 6.10 Snowload. 20 6.11 Earth pressure 21 6.12 Uplift pressure force. .22 6.13 Otherloads .22 Structural analysis .22 7.1 Calculation of member force. 22 7.2 Concrete. .22 7.2.1 Strength 22 7.2.2 Modulus of elasticity. .23 7.2.3 Poisson's ratio 23 7.2.4 Drying shrinkage .23 7.2.5 Creep 23 7.3 Steel 25 7.3.1 Strength 25 7.3.2 Modulus of elasticity .26 7.3.3 Relaxation 26 7.4 Calculation of tensile reinforcement .26 8 Stress limit. .27 8.1 General. 27 8.2 Stress limit of reinforced concrete members 28 8.2.1 Stress limit of concrete. 28 8.2.2 Stress limit of reinforcement 28 8.3 Stress limit of prestressed concrete members 28 8.3.1 Stress limit of concrete 28 8.3.2 Tensile stress limit of prestressing steel. 29 8.3.3 Stress limit of reinforcement... .29 8.3.4 Augmentation of tensile stress limit of concrete .29 9 Verification of safety against earthquake .29 9.1 Principles of seismic design... .29 9.1.1 General .29 iii