Prepared by the Task Committee on Electrical Transmission Line Structural Loading of the Electrical Transmission Structures Committee of the Special Design Issues Technical Administrative Committee of the Structural Engineering Institute of ASCE<\/i><\/b><\/p>\n
Fully revised and updated, Guidelines for Electrical Transmission Line Structural Loading, Fourth Edition,<\/em> MOP 74, provides the most current and relevant loading concepts and applications specific to transmission line design. A valuable resource for the development of a loading philosophy for electrical transmission structures, the information presented can be applied to an individual project or at a regional level. Key topics addressed in this manual are<\/p>\n This Manual of Practice will be an important guide to engineers involved in electrical utility and structural engineering.<\/p>\n ASCE Manuals and Reports on Engineering Practice 74: Guidelines for Electrical Transmission Line Structural Loading, Fourth Edition<\/b><\/p>\n\n
PDF Catalog<\/h4>\n
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\n PDF Pages<\/th>\n PDF Title<\/th>\n<\/tr>\n \n 2<\/td>\n Blank Page <\/td>\n<\/tr>\n \n 3<\/td>\n Guidelines for Electrical Transmission Line Structural Loading, 4E <\/td>\n<\/tr>\n \n 7<\/td>\n Contents <\/td>\n<\/tr>\n \n 11<\/td>\n Preface <\/td>\n<\/tr>\n \n 15<\/td>\n Acknowledgments <\/td>\n<\/tr>\n \n 17<\/td>\n 1. Overview of Transmission Line Structural Loading
1.0 Introduction <\/td>\n<\/tr>\n\n 18<\/td>\n 1.1 Principal Systems of a Transmission Line
1.1.1 Wire System <\/td>\n<\/tr>\n\n 19<\/td>\n 1.1.2 Structural Support System <\/td>\n<\/tr>\n \n 20<\/td>\n 1.2 Unique Aspects of Transmission Line Design
1.2.1 Tolerance of Failure <\/td>\n<\/tr>\n\n 21<\/td>\n 1.2.2 Designing to Contain Failure
1.2.3 Coordination of Strengths <\/td>\n<\/tr>\n\n 22<\/td>\n 1.2.4 Linear Exposure of Transmission Lines
1.3 Load and Resistance Factor Design (LRFD)
1.3.1 Reliability-Based Design <\/td>\n<\/tr>\n\n 23<\/td>\n 1.3.2 Overview of LRFD <\/td>\n<\/tr>\n \n 24<\/td>\n 1.3.3 Load Factors
1.3.4 Strength Factors <\/td>\n<\/tr>\n\n 25<\/td>\n 1.3.5 Sources for Nominal Strengths
1.3.6 Limit States <\/td>\n<\/tr>\n\n 26<\/td>\n 1.4 Weather-Related Loads
1.4.1 Extreme Winds
1.4.2 High-Intensity Winds <\/td>\n<\/tr>\n\n 27<\/td>\n 1.4.3 Extreme Ice with Concurrent Wind
1.5 Reliability Concepts for Weather-Related Loads
1.5.1 Mean Recurrence Intervals for Weather-Related Loads <\/td>\n<\/tr>\n\n 29<\/td>\n 1.5.2 Relative Reliability and Weather Event MRIs <\/td>\n<\/tr>\n \n 30<\/td>\n 1.5.3 Service Reliability versus Structural Reliability
1.6 Additional Load Considerations <\/td>\n<\/tr>\n\n 31<\/td>\n 1.6.1 Construction and Maintenance
1.6.2 Longitudinal and Failure Containment Loads <\/td>\n<\/tr>\n\n 32<\/td>\n 1.6.3 Earthquake Loads
1.6.4 Legislated Loads
1.6.5 Load Time Signature <\/td>\n<\/tr>\n\n 33<\/td>\n 1.7 Wire System
1.8 Examples <\/td>\n<\/tr>\n\n 34<\/td>\n 1.9 Appendixes
1.10 Draft Prestandard
1.11 Incorporation of Changing Data <\/td>\n<\/tr>\n\n 35<\/td>\n 2. Weather-Related Loads
2.0 Introduction <\/td>\n<\/tr>\n\n 36<\/td>\n 2.1 Wind Loading
2.1.1 Wind Force <\/td>\n<\/tr>\n\n 37<\/td>\n 2.1.2 Air Density Coefficient, Q
2.1.3 Basic Wind Speed <\/td>\n<\/tr>\n\n 41<\/td>\n 2.1.4 Wind Pressure Exposure Coefficient <\/td>\n<\/tr>\n \n 46<\/td>\n 2.1.5 Gust Response Factor <\/td>\n<\/tr>\n \n 50<\/td>\n 2.1.6 Force Coefficient <\/td>\n<\/tr>\n \n 60<\/td>\n 2.1.7 Topographic Effects <\/td>\n<\/tr>\n \n 64<\/td>\n 2.1.8 Application of Wind Loads to Latticed Towers <\/td>\n<\/tr>\n \n 65<\/td>\n 2.2 High-Intensity Winds
2.2.1 Downbursts <\/td>\n<\/tr>\n\n 67<\/td>\n 2.2.2 Tornadoes <\/td>\n<\/tr>\n \n 72<\/td>\n 2.3 Ice and Wind Loading
2.3.1 Introduction
2.3.2 Categories of Icing <\/td>\n<\/tr>\n\n 73<\/td>\n 2.3.3 Design Assumptions for Ice Loading
2.3.4 Ice Accretion on Wires Due to Freezing Rain <\/td>\n<\/tr>\n\n 81<\/td>\n 2.3.5 Ice Accretion on Structural Members <\/td>\n<\/tr>\n \n 82<\/td>\n 2.3.6 Unbalanced Ice Loads
2.3.7 Ice Accretion on Aerial Marker Balls or Similar Devices <\/td>\n<\/tr>\n\n 85<\/td>\n 3. Additional Load Considerations
3.0 Introduction
3.1 Longitudinal Loads, Line Security, and Failure Containment
3.1.1 Longitudinal Loads <\/td>\n<\/tr>\n\n 86<\/td>\n 3.1.2 Unbalanced Loads on Intact Systems
3.1.3 Longitudinal Loads due to Non-Intact Wire Systems
3.1.4 Failure Containment and Line Security Loads <\/td>\n<\/tr>\n\n 87<\/td>\n 3.2 Construction and Maintenance Loads
3.2.1 General
3.2.2 Structure Erection <\/td>\n<\/tr>\n\n 89<\/td>\n 3.2.3 Loads Due to Wire Installation <\/td>\n<\/tr>\n \n 92<\/td>\n 3.2.4 Maintenance Loads <\/td>\n<\/tr>\n \n 93<\/td>\n 3.3 Worker Access and Fall Protection Loads
3.4 Wind-Induced Structure Vibration <\/td>\n<\/tr>\n\n 94<\/td>\n 3.5 Wire Galloping Load Considerations <\/td>\n<\/tr>\n \n 95<\/td>\n 3.5.1 Wire Galloping Loads <\/td>\n<\/tr>\n \n 96<\/td>\n 3.5.2 Galloping Mitigation
3.6 Earthquake Loads <\/td>\n<\/tr>\n\n 97<\/td>\n 3.6.1 Seismic Hazards <\/td>\n<\/tr>\n \n 98<\/td>\n 3.6.2 Siting and Geotechnical Assessment
3.7 Summary of Additional Load Considerations <\/td>\n<\/tr>\n\n 101<\/td>\n 4. Wire System
4.0 Introduction <\/td>\n<\/tr>\n\n 102<\/td>\n 4.1 Tension Section
4.2 Wire Condition <\/td>\n<\/tr>\n\n 104<\/td>\n 4.3 Wire Tension Limits <\/td>\n<\/tr>\n \n 105<\/td>\n 4.4 Calculated Wire Tension
4.4.1 The Ruling Span Method <\/td>\n<\/tr>\n\n 106<\/td>\n 4.4.2 Structural Analysis of a Single Tension Section
4.4.3 Structural Analysis of Multiple Tension Sections
4.4.4 Computational Methods <\/td>\n<\/tr>\n\n 107<\/td>\n 4.5 Loads at Wire Attachment Points
4.5.1 Wire Unit Loads
4.5.2 Using Wind and Weight Spans <\/td>\n<\/tr>\n\n 111<\/td>\n 4.5.3 Weight Spans on Inclined Spans <\/td>\n<\/tr>\n \n 112<\/td>\n 4.5.4 Weight Span Change with Blow-Out on Inclined Spans <\/td>\n<\/tr>\n \n 114<\/td>\n 4.5.5 Centerline Horizontal Angle versus Wire Horizontal Angle <\/td>\n<\/tr>\n \n 115<\/td>\n 5. Examples
5.0 Latticed Suspension Tower Loads <\/td>\n<\/tr>\n\n 116<\/td>\n 5.0.1 Design Data <\/td>\n<\/tr>\n \n 118<\/td>\n 5.0.2 Extreme Wind (Chapter 2, Section 2.1) <\/td>\n<\/tr>\n \n 120<\/td>\n 5.0.3 Wind at 30\u00b0: Extreme Wind at 30\u00b0 Yaw Angle (Chapter 2, Section 2.1) <\/td>\n<\/tr>\n \n 122<\/td>\n 5.0.4 Extreme Radial Glaze Ice with Wind (Chapter 2, Section 2.3) <\/td>\n<\/tr>\n \n 123<\/td>\n 5.0.5 Construction and Maintenance (Chapter 3, Section 3.1) <\/td>\n<\/tr>\n \n 125<\/td>\n 5.0.6 Failure Containment (Chapter 3, Section 3.1.4 and Appendix I, Section 1.3.1) <\/td>\n<\/tr>\n \n 126<\/td>\n 5.1 Weight Span Change with Blowout on Inclined Spans <\/td>\n<\/tr>\n \n 127<\/td>\n Shield Wire <\/td>\n<\/tr>\n \n 128<\/td>\n Conductor <\/td>\n<\/tr>\n \n 129<\/td>\n 5.2 Traditional Catenary Constant
Shield Wire <\/td>\n<\/tr>\n\n 130<\/td>\n Conductor <\/td>\n<\/tr>\n \n 131<\/td>\n Appendixes
A. Definitions, Notations, and SI Conversion Factors <\/td>\n<\/tr>\n\n 139<\/td>\n B. Reliability-Based Design <\/td>\n<\/tr>\n \n 141<\/td>\n C. Air Density Coefficient, Q <\/td>\n<\/tr>\n \n 143<\/td>\n D. Conversion of Wind Speed Averaging Time <\/td>\n<\/tr>\n \n 145<\/td>\n E. Supplemental Information on Structure Vibration <\/td>\n<\/tr>\n \n 149<\/td>\n F. Equations for Gust Response Factors <\/td>\n<\/tr>\n \n 163<\/td>\n G. Supplemental Information on Force Coefficients <\/td>\n<\/tr>\n \n 183<\/td>\n H. Supplemental Information on Ice Loading <\/td>\n<\/tr>\n \n 195<\/td>\n I. Supplemental Information Regarding Longitudinal Loads <\/td>\n<\/tr>\n \n 211<\/td>\n J. Investigation of Transmission Line Failures <\/td>\n<\/tr>\n \n 225<\/td>\n K. High-Intensity Winds <\/td>\n<\/tr>\n \n 261<\/td>\n L. Weather-Related Loads for Additional MRIs <\/td>\n<\/tr>\n \n 273<\/td>\n M. Draft Pre-Standard Minimum Design Loads for Electrical Transmission Line Facilities <\/td>\n<\/tr>\n \n 303<\/td>\n References <\/td>\n<\/tr>\n \n 317<\/td>\n Index <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" \n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n ASCE<\/b><\/a><\/td>\n 2020<\/td>\n 324<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":234607,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2660],"product_tag":[],"class_list":{"0":"post-234604","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-asce","8":"first","9":"instock","10":"sold-individually","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/234604","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/234607"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=234604"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=234604"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=234604"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}