Title

Dynamic analysis of guyed antenna towers for seismic loads.

Date of Award

2005

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Civil and Environmental Engineering

Keywords

Engineering, Civil.

Rights

CC BY-NC-ND 4.0

Abstract

The increasing demand for personal communication services (PCS), such as digital cell phones and pagers, as well as digital television (DTV), has created new challenges for creating and maintaining telecommunications towers. For such communication tools, antenna towers are the best choice because they are relatively economical and effective for remote transmission, especially in North America where land area is large. Wireless firms are further pressured to complete digital systems within the next five years and to provide "seamless" coverage. The Canadian Standard for Antennas, Towers and Antenna-Supporting Structures, CSA-S37-01, provides guidance for seismic analysis of lattice towers. However, simplified design method for equivalent static forces for seismic analysis of guyed towers that covers different zones in North America is as yet unavailable especially for towers 300 m high and up. Furthermore, the upcoming (2005) National Building Code of Canada introduces new seismic hazard values in which the spectral levels of seismic loads are changed based on probabilistic response spectra of earthquake events. Analysis for guyed towers based on these hazard levels is not yet available. In addition, the American Society of Civil Engineers Task Committee on the Dynamic Response of Lattice Towers has recently stated that "No approximate static method has been proposed yet for the seismic analysis of guyed masts". The objectives of this research are to evaluate the seismic performance of guyed telecommunication towers in North America, to contribute to the efficient design of such towers by developing computer-based, analytical models capable of predicting accurately their response when subjected to seismic loading conditions, and to provide guidelines for the Performance Based Design (PBD) of such structures. The study incorporated 24 earthquake records and nine tall guyed telecommunication towers with heights varying from 60 to 591 m. The study proposes a simplified design method for the equivalent static forces due to the effect of seismic loading on guyed towers. This method can be used to predict the envelope of the base shear, bending moment, vertical reaction in the mast of guyed towers as well as the maximum tension in the guys along the elevation of the mast.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .M475. Source: Dissertation Abstracts International, Volume: 66-07, Section: B, page: 3847. Thesis (Ph.D.)--University of Windsor (Canada), 2005.