EFFECT OF ROOF TOP TOWERS ON LATERAL LOAD ANALYSIS OF THE BUILDINGS

Abstract

5 Towers are important structural components used for various purposes in today’s life. Communication and transmission line towers are widely used to transmit data and electricity respectively over long distances. Transmission line towers essentially rest on ground due to their large dimensions. Communication towers either rest on ground or are installed on the roof top of the buildings depending on the size of the tower and also on the availability of the space. The roof top communication towers are mainly used in metropolitan cities like Delhi where the space is available at a premium and the rapid expansion of the telecom network has necessitated their installation in large number. The advantage of a roof top tower is the utilization of the height of the building in covering a greater area. The close proximity of such towers permits them to be of small height up to 20 metres. The common practice for analyzing roof top towers is to first analyze the tower as a separate structure and then transfer the forces generated in this tower to the building where it is to be installed. The wind forces in the tower are calculated by assuming it to be standing on the roof top. This report tries to differ in this approach by modeling the tower as a part of a three and a six storey building located in Delhi and compares the results with that of traditional methodology. The position of a tower on the plan of the building is likely to affect the forces generated in the tower as well as in the building. This aspect can be studied by modeling the tower at different positions on the plan of the building and comparing various parameters like the time period of the combined system, forces and moments generated in the building and in the tower and the displacements at the locations where the tower is supported on to the building. Similarly the effect of the tower on the building will vary with increasing building height. This report analyzes this effect by repeating the numerical study for a six storey building.