Communication Structures

This book combines the accumulated knowledge of structural engineers, scientific researchers, mast and tower owners and antenna experts with experience in the analysis, design, construction and operation of communication structures, into one accessible volume. It introduces the reader to the basis of design, analysis and construction of lattice towers and guyed masts used for communication purposes (radio, television, mobile phones and radar) and looks at new developments and the effects on the industry. The author focuses on the light and wind sensitive structures that support the aerials that make communication services possible and states that the design and construction of these structures involves significant engineering expertise to ensure that they are safe and reliable, yet cost effective and efficient. A brief history of tall structures is provided and the various types of structure, dictated by their function and/or location are described. The loading on such structures is described and the methods of calculating their response outlined. Dynamic effects from vortex shedding or galloping are outlined, together with detailed guidance on how to minimise these effects and how to assess fatigue life. The book provides detailed information on: history, design considerations and failures meteorological parameters, wind resistance and strength aerodynamic stability, fatigue, access and safety codes of practice and design standards. Communication Structures is essential for both the established and the new generation of engineers, telecom administrators, contractors, masts and tower fabricators and related professionals.

Table of Contents:
History Design considerations, General, Choice of site, Choice of structure, Economic considerations, Environmental considerations, Electronic considerations, General, Antenna characteristics, Low-frequency antennas, Medium-frequency antenna systemsVHF and UHF antennas, Digital audio broadcasting, Mobile phone antennas, Effect on existing services of subsequent additional antennas Failures of masts and towers, GeneralIcing failures, Design/detail failures, Maintenance failures, Aircraft damage, Vandal damage, Lessons to be learned Forms of structure, General, Timber towers, Concrete towers, Lattice steel towers, Lattice guyed masts, Tubular guyed masts, Concrete guyed masts, Other forms of communication structures Meteorological parameters, GeneralWind, Wind climate, Boundary layer, Serviceability wind speeds, Atmospheric icing, GeneralPhysics and theoretical modelling of ice accretion, Empirical models to estimate ice loads on Structures, Earthquakes, Temperature, Other meteorological aspects Wind resistance, General, Symmetrical structures without ancillaries, Symmetrical structures with limited ancillaries, General method for structures containing ancillariesLinear ancillaries, Discrete ancillaries, CablesCommunications structures, Measurements on scale model of communications tower, Discrepancy between wind tunnel tests and full-scale measurements, Icing Response, General, Lattice towers, Guyed masts, General, Frequency domain analysis, Time domain analysis, Simplified methods, Summary Strength, Introduction, Design against buckling — individual members, General, Influence of local and torsional buckling, Angle leg members, Angle bracing members, Tubular leg members, Tubular bracing members, Solid round members, Secondary members (`redundants’)Bracing types, Compound members, Tension, Connections, General, Flange joints in tubular or solid round leg members, Guy connections Cables, General, Types of cables, Strength of guy ropes, Rotational characteristics of steel ropes, Modulus of elasticity, Prestretching, Still air tension, Terminations, General, Types of terminations Aerodynamic stability, General, Vortex shedding, GeneralBackground and critical wind speed, Practical implications, Damping devices, Galloping, General, Critical wind speed, Damping devices Fatigue, General, Lattice towers, Lattice masts, Guys Foundations,General,Foundation types,Type I: to resist upliftType II: to resist overturningType III: to resist down thrustType IV: guy anchorages Codes and standards,History General, Wind loadingIce loading, Strength, Other aspects, Current codes, Communications structures, GeneralComparison of current, Codes Access and safety, General, IASS Recommendations for safe access Fabrication and erection, Materials and fabrication, Steel for towers and mast columns, Aluminium, Timber, Plastics, Erection, General, Erection of lattice towers,Constraints, Minimizing maintenance at the design stage, Manuals Seismic response, General, Seismicity and earthquake-resistance performance levels, Prediction of seismic response of structures, General, Self-supporting lattice towers, Monopoles, Guyed masts, Antennas and ancillary components, Geotechnical considerations Annex A Codes of Practice and Design Standards, General, Comparisons of National Codes, Scope, Limit states/reliability classes, Wind structure, Wind resistance, Ice loading, Displacements/serviceability, Partial safety factors, Strength, Compressive strength, Tensile strength, Guy assemblies, Prestretching, Terminations, Initial tensions, Erection, Insulators, Access Annex B IASS Working Group Number 4: Masts and Towers, Brief history, Role in the future, The members of the Group, References, Index