Analysis of four leg telecommunication towers for seismic loading using response spectrum method

Abstract

Telecommunication towers are common sight even in very remote areas of Sri Lanka with the revolutionary development in this sector during last few decades. These towers play a vital role especially in wireless communication. Hence, a failure of such tower in a disaster like an earthquake is a major concern since it hampers communication needs in rescue operations during the disaster. Further, since these are usually tall structures, failure of tower may itself cause a significant damage. However, almost all existing telecommunication towers in this country have not been checked for seismic loading since Sri Lanka was considered as a country free from earthquakes until recently. But, now most of the structural engineers consider seismic effects for their designs of important structure such as high rise buildings, dams, etc. Still, this practice has not been implemented regarding telecommunication tower designs. This paper discuss the structural performance of selected existing four legged Greenfield towers which were analyzed under seismic loadings using Response Spectrum method given in ANSI/TIA-222-G. Approach of analysis and comparison of analytical results under different seismic analytical techniques as well as with results under wind loading are presented in this paper.