1、 ASCE Manuals and Reports on Engineering Practice No. 74Guidelines for Electrical Transmission Line Structural LoadingThird EditionPrepared bythe Task Committee on Structural Loadings ofthe Committee on Electrical Transmission Structures of the Structural Engineering Institute ofthe American Society
2、 of Civil EngineersEdited byC. Jerry WongMichael D. MillerLibrary of Congress Cataloging-in-Publication DataGuidelines for electrical transmission line structural loading / prepared by the Task Committee on Structural Loadings of the Committee on Electrical Transmission Structures of the Structural
3、Engineering Institute of the American Society of Civil Engineers ; edited by C. Jerry Wong.3rd ed.p. cm.(ASCE manuals and reports on engineering practice ; no. 74)Includes bibliographical references and index.ISBN 978-0-7844-1035-6 (alk. paper)1. Electric linesPoles and towersDesign and construction
4、. 2. Load factor design.I. Wong, C. Jerry. II. American Society of Civil Engineers. Task Committee on Structural Loadings.TK3242.G77 2009621.31922dc222009033203Published by American Society of Civil Engineers1801 Alexander Bell DriveReston, Virginia 20191www.pubs.asce.orgAny statements expressed in
5、these materials are those of the individual authors and do not necessarily represent the views of ASCE, which takes no responsibility for any statement made herein. No reference made in this publication to any specifi c method, product, process, or service constitutes or implies an endorsement, reco
6、mmendation, or warranty thereof by ASCE. The materials are for general information only and do not represent a standard of ASCE, nor are they intended as a reference in purchase specifi cations, contracts, regulations, statutes, or any other legal document.ASCE makes no representation or warranty of
7、 any kind, whether express or implied, concerning the accuracy, completeness, suitability, or utility of any information, apparatus, product, or process discussed in this publication, and assumes no liability therefor. This information should not be used without fi rst securing competent advice with
8、 respect to its suitability for any general or specifi c application. Anyone utilizing this information assumes all liability arising from such use, including but not limited to infringement of any patent or patents.ASCE and American Society of Civil EngineersRegistered in U.S. Patent and Trademark
9、Offi ce.Photocopies and reprints. You can obtain instant permission to photocopy ASCE publica-tions by using ASCEs online permission service (http:/pubs.asce.org/permissions/requests/). Requests for 100 copies or more should be submitted to the Reprints Department, Publications Division, ASCE (addre
10、ss above); e-mail: permissionsasce.org. A reprint order form can be found at http:/pubs.asce.org/support/reprints/.Copyright 2010 by the American Society of Civil Engineers.All Rights Reserved.ISBN 978-0-7844-1035-6Manufactured in the United States of America.17 16 15 14 13 12 11 10 1 2 3 4 5MANUALS
11、 AND REPORTS ON ENGINEERING PRACTICE(As developed by the ASCE Technical Procedures Committee, July 1930, and revised March 1935, February 1962, and April 1982)A manual or report in this series consists of an orderly presentation of facts on a particular subject, supplemented by an analysis of limita
12、tions and applications of these facts. It contains information useful to the average engineer in his or her everyday work, rather than fi ndings that may be useful only occasionally or rarely. It is not in any sense a “stan-dard,” however; nor is it so elementary or so conclusive as to provide a “ru
13、le of thumb” for nonengineers.Furthermore, material in this series, in distinction from a paper (which expresses only one persons observations or opinions), is the work of a committee or group selected to assemble and express information on a specifi c topic. As often as practicable, the committee i
14、s under the direction of one or more of the Technical Divisions and Councils, and the product evolved has been subjected to review by the Executive Committee of the Division or Council. As a step in the process of this review, proposed manuscripts are often brought before the members of the Technica
15、l Divi-sions and Councils for comment, which may serve as the basis for improvement. When published, each work shows the names of the com-mittees by which it was compiled and indicates clearly the several pro-cesses through which it has passed in review, in order that its merit may be defi nitely un
16、derstood.In February 1962 (and revised in April 1982) the Board of Direction voted to establish a series entitled “Manuals and Reports on Engineering Practice,” to include the Manuals published and authorized to date, future Manuals of Professional Practice, and Reports on Engineering Practice. All
17、such Manual or Report material of the Society would have been ref-ereed in a manner approved by the Board Committee on Publications and would be bound, with applicable discussion, in books similar to past Manuals. Numbering would be consecutive and would be a continuation of present Manual numbers.
18、In some cases of reports of joint committees, bypassing of Journal publications may be authorized.MANUALS AND REPORTS ON ENGINEERING PRACTICE CURRENTLY AVAILABLENo. Title40 Ground Water Management45 Consulting Engineering: A Guide for the Engagement of Engineering Services49 Urban Planning Guide50 P
19、lanning and Design Guidelines for Small Craft Harbors54 Sedimentation Engineering57 Management, Operation and Maintenance of Irrigation and Drainage Systems60 Gravity Sanitary Sewer Design and Construction, Second Edition62 Existing Sewer Evaluation and Rehabilitation66 Structural Plastics Selection
20、 Manual67 Wind Tunnel Studies of Buildings and Structures68 Aeration: A Wastewater Treatment Process71 Agricultural Salinity Assessment and Management73 Quality in the Constructed Project: A Guide for Owners, Designers, and Constructors74 Guidelines for Electrical Transmission Line Structural Loadin
21、g, Third Edition77 Design and Construction of Urban Stormwater Management Systems80 Ship Channel Design81 Guidelines for Cloud Seeding to Augment Precipitation82 Odor Control in Wastewater Treatment Plants84 Mechanical Connections in Wood Structures85 Quality of Ground Water91 Design of Guyed Electr
22、ical Transmission Structures92 Manhole Inspection and Rehabilitation, Second EditionNo. Title93 Crane Safety on Construction Sites94 Inland Navigation: Locks, Dams, and Channels95 Urban Subsurface Drainage97 Hydraulic Modeling: Concepts and Practice98 Conveyance of Residuals from Water and Wastewate
23、r Treatment100 Groundwater Contamination by Organic Pollutants: Analysis and Remediation101 Underwater Investigations103 Guide to Hiring and Retaining Great Civil Engineers104 Recommended Practice for Fiber-Reinforced Polymer Products for Overhead Utility Line Structures105 Animal Waste Containment
24、in Lagoons106 Horizontal Auger Boring Projects107 Ship Channel Design and Operation108 Pipeline Design for Installation by Horizontal Directional Drilling109 Biological Nutrient Removal (BNR) Operation in Wastewater Treatment Plants110 Sedimentation Engineering: Processes, Measurements, Modeling, an
25、d Practice111 Reliability-Based Design of Utility Pole Structures112 Pipe Bursting Projects113 Substation Structure Design Guide114 Performance-Based Design of Structural Steel for Fire Conditions115 Pipe Ramming Projects116 Navigation Engineering Practice and Ethical Standards117 Inspecting Pipelin
26、e Installation118 Belowground Pipeline Networks for Utility Cables119 Buried Flexible Steel Pipe: Design and Structural AnalysisPREFACESince the original publication of Manual 74 in 1991, and the preceding “Guidelines for Transmission Line Structural Loading” in 1984, the understanding of structural
27、 loadings on transmission line structures has broadened signifi cantly. However, improvements in computational capa-bility have enabled the transmission line engineer to more easily deter-mine structural loadings without properly understanding the parameters that affect these loads. Many seasoned pr
28、ofessionals have expressed concern for the apparent lack of recent information on the topic of struc-tural loadings as new engineers enter this industry. The Committee on Electrical Transmission Structures is charged with the responsibility to report, evaluate, and provide loading requirements of tr
29、ansmission struc-tures. This task committee was therefore formed to update and revise the 1991 manual.The recommendations presented herein are the consensus opinion of the task committee members. Although the subject matter of this guide has been thoroughly researched, it should be applied only in t
30、he context of sound engineering judgment.The committee wishes to thank the Peer Review Committee members for their assistance and contributions to this document: Anthony M. DiGioia (Chair), Mark Allen, Alan G. Davenport, Elias Ghannoun, John W. Harrison, and Robert Morris. Also, the committee is gra
31、teful for the comments and guidance of Leon Kempner Jr. and Dan Jackman.It is with much appreciation that we acknowledge the contributions of Task Committee member Jerome G. Hanson and Peer Review Committee member John W. Harrison, who are no longer with us.Respectfully submitted,Task Committee on S
32、tructural Loadingsvvi PREFACEFrank W. Agnew Harry V. Durden John D. MozerRichard F. Aichinger William Y. Ford Robert E. Nickerson Jim Andersen Bruce Freimark Wesley J. OliphantCarl W. Austin Jim Hogan Mark OstendorpTerry G. Burley Magdi Ishac Alain PeyrotRonald J. Carrington Kathy Jones Larry ShanMi
33、chael S. Cheung James M. McGuire David TennentHabib J. Dagher Kishor C. Mehta George T. WatsonNicholas J. DeSantis Michael D. Miller C. Jerry Wong (Chair)CONTENTSFOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix1 OVERVIEW OF LOAD CRITERIA . . .
34、 . . . . . . . . . . . . . . . . . . . . . . 11.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Principal Systems of a Transmission Line . . . . . . . . . . . . . . . . . . . . 21.2 Loads and Relative Reliability. . . . . . . . . . . . .
35、. . . . . . . . . . . . . . . . . 31.3 Wire Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.4 Limit States Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 WEATHER-RELATED LOADS. . . . . . . . . . . . . . . .
36、. . . . . . . . . . . . . 212.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212.1 Extreme Wind. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222.2 High-Intensity Winds . . . . . . . . . . . . . . . .
37、. . . . . . . . . . . . . . . . . . . . . 422.3 Ice and Wind Loading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 ADDITIONAL LOAD CONSIDERATIONS. . . . . . . . . . . . . . . . . 593.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38、 . . . . . . . . . 593.1 Construction and Maintenance Loads . . . . . . . . . . . . . . . . . . . . . . . 593.2 Fall Protection Loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 623.3 Longitudinal Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39、. . . . . . 633.4 Structure Vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 673.5 Conductor Galloping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 683.6 Earthquake Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40、 . . . . . . . . . . 694 WIRE SYSTEM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 714.0 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 714.1 Tension Section . . . . . . . . . . . . . . . . . . . . . . . .
41、 . . . . . . . . . . . . . . . . . . 71viiviii CONTENTS4.2 Wire Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 724.3 Wire Tension Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 734.4 Calculated Wire Tension . . . . .
42、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 744.5 Loads at Wire Attachment Points . . . . . . . . . . . . . . . . . . . . . . . . . . 764.6 Extreme Wind on Wire System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 804.7 Combined Wind and Ice on Wire System . . . . . . . . .
43、 . . . . . . . . . . . 805 EXAMPLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 815.0 Latticed Suspension Tower Loads . . . . . . . . . . . . . . . . . . . . . . . . . . 815.1 Weight Span Change with Blow-out on Inclined Spans . . . . . . . 905.2 Tradi
44、tional Catenary Constant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91APPENDIX A DEFINITIONS, NOTATIONS, AND SI CONVERSION FACTORS . . . . . . . . . . . . . . . . . 93APPENDIX B LIMITATIONS OF RELIABILITY-BASED DESIGN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45、. . . 99APPENDIX C NUMERICAL CONSTANT, Q . . . . . . . . . . . . . . . . . 105APPENDIX D CONVERSION OF WIND SPEED AVERAGING TIME . . . . . . . . . . . . . . . . . . . . . . . . . . 107APPENDIX E SUPPLEMENTAL INFORMATION ON STRUCTURE VIBRATION . . . . . . . . . . . . . . . . . . . . 109APPENDIX F EQU
46、ATIONS FOR GUST RESPONSE FACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113APPENDIX G SUPPLEMENTAL INFORMATION ON FORCE COEFFICIENTS . . . . . . . . . . . . . . . . . . . . . . 119APPENDIX H SUPPLEMENTAL INFORMATION ON ICE LOADING . . . . . . . . . . . . . . . . . . .
47、. . . . . . . . . . . 139APPENDIX I SUPPLEMENTAL INFORMATION ON SPECIAL LOADS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151APPENDIX J INVESTIGATION OF TRANSMISSION LINE FAILURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163REFERENCES . . . . . . . . . . . . . . . . . .
48、. . . . . . . . . . . . . . . . . . . . . . . . . . . . 173INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185FOREWORDBACKGROUNDThis new edition of Guidelines for Electrical Transmission Line Structural Loading (Manual 74) has been prom
49、pted by the need to introduce several major changes to the most recent Manual 74 (1991), as well as to have an opportunity to better defi ne or refi ne some of the minor issues addressed in the previous document.The previous editions (1984, 1991) have been well received and found wide use as practical guides to supplement the mandatory specifi cs pre-scribed by the National Electrical Safety Code (NESC) or other state requirements, which are intended to be legal minimums to set safety standards for the
