1、 AWWA Standard SM Design of Prestressed Concrete Cylinder Pipe Effective date: May 1, 2015. First edition approved by AWWA Board of Directors June 18, 1992. This edition approved Jan. 19, 2014. Approved by American National Standards Institute Sept. 9, 2014. ANSI/AWWA C304-14 (Revision of ANSI/AWWA
2、C304-07) Copyright 2014 American Water Works Association. All Rights Reserved. ii AWWA Standard This document is an American Water Works Association (AWWA) standard. It is not a specification. AWWA standards describe minimum requirements and do not contain all of the engineering and administrative i
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11、ds may receive current information on all standards by calling or writing the American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036; 212.642.4900; or emailing infoansi.org. ISBN-13, print: 978-1-62576-050-0 eISBN-13, electronic: 978-1-61300-312-1DOI: http:/dx.d
12、oi.org/10.12999/AWWA.C304.14 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information or retrieval system, except in the form of brief excerpts or quotations for review
13、purposes, without the written permission of the publisher. Copyright 2015 by American Water Works Association Printed in USA hours of work by your fellow water professionals. Revenue from the sales of this AWWA material supports ongoing product development. Unauthorized distribution, either electron
14、ic or photocopied, is illegal and hinders AWWAs mission to support the water community. This AWWA content is the product of thousands of Copyright 2014 American Water Works Association. All Rights Reserved. iii Committee Personnel The AWWA Standards Subcommittee on ANSI/AWWA C304, which reviewed and
15、 developed this standard, had the following personnel at the time: Armand W. Tremblay, Chair J.G. Grunow, Louisville Water Company, Louisville, Ky. (AWWA) J.J. Roller, CTLGroup, Skokie, Ill. (AWWA) A.W. Tremblay, Tipp City, Ohio (AWWA) J.A. Tully, Munro Ltd., Utopia, Ont., Canada (AWWA) M.S. Zargham
16、ee, Simpson Gumpertz and (2) embedded-cylinder pipe (ECP), with a core composed of a steel cylinder encased in concrete, which is subsequently prestressed with high-tensile wire wrapped around the exterior concrete surface. The cores of both types of pipe are coated with portland-cement mortar. Befo
17、re the procedures and requirements contained in this document were devel- oped, the design of PCCP was determined by two distinct procedures. These were des- ignated methods A and B described in appendixes A and B of ANSI/AWWA C301-84, Prestressed Concrete Pressure Pipe, Steel-Cylinder Type, for Wat
18、er and Other Liquids. Method A used a semiempirical approach based on (1) W o, which is nine-tenths of the three-edge bearing test load that causes incipient cracking; and (2) the theoretical hydrostatic pressure, P o , which relieves the calculated residual compression in the con- crete core as a r
19、esult of prestressing. The allowable combinations of three-edge bearing load and internal pressure were determined by a cubic parabola, passing through W oand P o, which defined the limits of these combinations. The three-edge bearing loads used in method A were converted to earth loads and transien
20、t external loads using bed- ding factors provided in AWWA Manual M9, Concrete Pressure Pipe (1979) and in the ACPA Concrete Pipe Design Manual (1988). Method B was based on a procedure that limited the maximum combined net tensile stress in pipe under static external load and internal pressure to a
21、value equal to 7.5 f c , where f c= the 28-day compressive strength of core concrete in psi (0.62 f c , where f c= the 28-day compressive strength of core concrete in MPa). Both design methods limited the working pressure to P ofor ECP and to 0.8P ofor LCP, where P owas the internal pressure require
22、d to overcome all compression in * American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036. American Concrete Pipe Association, 1303 West Walnut Hill Lane, Suite 305, Irving, TX 75038. Copyright 2014 American Water Works Association. All Rights Reserved. x the co
23、re concrete excluding external load. Under transient conditions, such as those produced by surge pressures and live loads, both methods permitted increased internal pressure and external load. Although the two methods of design produced similarly conservative results that served PCCP users well for
24、nearly half a century, a unified method of design, described in this standard, was developed to replace methods A and B. The following objectives for the unified design procedure were established: 1. It should replace both existing methods, the semiempirical method A and the working stress method B,
25、 described in ANSI/AWWA C301-84. 2. It should be based on state-of-the-art procedures for the design and analysis of concrete and prestressed concrete structures. 3. It should account for the state of prestress in the pipe, as well as the com- bined effects of external loads, pipe and fluid weights,
26、 and internal pressures. 4. It should agree with the results of 40 years of experimental data gathered by the American concrete pressure-pipe industry. 5. It should preclude the onset of visible cracking under working plus transient conditions. 6. It should provide adequate safety factors based on e
27、lastic and strength limit states. The method of calculating residual stresses in the concrete core, the steel cylinder, and the prestressing wire was updated to separately account for the effects of elastic deformation, creep, and shrinkage of concrete, and the relaxation of the prestressing wire (Z
28、arghamee, Heger, and Dana 1988a; see appendix B). Intrinsic wire relaxation, creep factors, and shrinkage strains obtained from procedures recommended by ACI *Com- mittee 209 (1982) (ACI 1982; see appendix B) were used in a step-by-step integration procedure (Zarghamee 1990; see appendix B) to evalu
29、ate the time-related variations of stress in the pipe elements. The results of the step-by-step integration procedure, applied to pipe in a buried environment, were used to develop simplified equations for practical design use. Calculations of the design creep factor and shrinkage strain for buried
30、pipe are based on the procedures recommended by ACI Committee 209. Creep and shrinkage are computed as functions of time, relative humidity, volume-to-surface ratio, age at loading, curing duration, concrete composition, and method of placement. Design val- ues for creep factor and shrinkage strain are based on a 50-year exposure of pipe to the * American Concrete Institute, 38800 Country Club Drive, Farmington Hills, MI 48331. Copyright 2014 American Water Works Association. All Rights Reserved.
