Seismic analysis of three legged lattice telecommunication towers for Sri Lanka conditions

Abstract

Mobile communication is feeing an exponential growth and thousands of telecommunication towers have been constructed in Sri Lanka to accommodate the current demand. Failure of communication tower in a disaster like an earthquake is of major concern as this can hinder the communication needs, especially in case of rescue operation. It also causes property damage to itself and adjacent structures. Hence, design of telecommunication towers considering all possible extreme conditions are essential Sri Lanka is considered earthquake free as it is fer away from earthquake prone regions and almost all local telecommunication towers were not checked against earthquake. However designers have started to think about earthquake design of structures as frequent tremors are recorded in recent past due to intra plate earthquakes. Objective of this research is assessing the performance of existing three leg self-supporting towers which were not designed for seismic loadings and find strategies for retrofitting in case of significant adverse effect This paper presents the analytical results of three legged lattice telecommunication towers in different heights under seismic loading for local conditions. Such results indicate that structural actions under local seismic loading condition are comparatively insignificant when compared with same under wind loads for the selected telecommunication towers.