Gauge Newsletter January 2020 | Page 7

Wind-Induced Fatigue Analysis Since Colombo is a coastal city, the Lotus Tower faces continuous sea breeze. Apart from that, the tower can be subjected to a very large number of cycles of fluctuating wind loads. The wind forces acting on wind sensitive structures depend on factors such as wind speed and wind effects. Therefore, the tower was tested using code methods, computational fluid dynamics methods and wind tunnel tests to maintain stability from the wind. Modern fluid-structure interaction techniques were used to predict accelerations and then they were validated with wind tunnel test results. These tests were conducted by the China Academy of Building Research (CABR) in Beijing. 1:300 scale model test was carried out in the CABR wind tunnel. This wind tunnel is an open-circuit wind tunnel with a total length of 96.5 meters and has been configured with two test sections. The Mast The design of the Lotus Tower includes a slender concrete and steel antenna mast which is approximately 88 meters tall, extending from a level of approximately 262m to 350m above ground level. This mast has been designed for a life time of 50 years. The structure of the mast which is 96.8 meters in height has four sections as square, octagonal, square and square cross-sections respectively. This has been designed to accommodate 20 television broadcasting companies, 50 FM broadcasters and telecom operators. “ Unique landmark in Colombo sky ” “ 356m ” • The tallest completed tower in South Asia • 11th tallest completed tower in Asia • 19th tallest completed tower in the world GAUGE Magazine University of Peradeniya Page 5