Faculty of Civil Engineering, Universiti Teknology, Malaysia
Specific design codes for telecommunication towers indicate wind load as the governing lateral load and except in limited cases, do not consider earthquake load in the design of these structures. Moreover in these codes evaluation of seismic behavior of self-supporting telecommunication towers has been limited to linear behavior with no consideration to nonlinear behavior of these structures. In this study, seismic performances of ten existing 4-legged telecommunication towers with heights ranging from 18 to 67 meter have been investigated. These towers have been designed and installed in Iran. At first, nonlinear static analysis has been applied to all towers. For this purpose, three different vertical distributions of lateral load have been utilized. Then, both target displacement approach and capacity spectrum approach have been considered to calculate the seismic performance point of towers. It has been exhibited that all towers have been satisfied immediate occupancy level for both design base earthquake hazard level and maximum probable earthquake hazard level. At last, three equations have been presented to estimate towers yield base shear and base shear that corresponds to immediate occupancy level for 4-legged self-supporting telecommunication towers for both mentioned seismic hazard level.
Self-supporting 4-legged Telecommunication Tower, Nonlinear Static Analysis, Seismic Performance Level, Seismic Hazard Level
