INTERACTION BETWEEN ROOFTOP TOWER AND HOST STRUCTURE

Abstract

The increasing trend of mobile communications has seen exponential growth in the last few years. Increased competitions among mobile operators also have contributed to the installation of many towers to enhance both coverage area and network reliability. The tower locations as specified in terms of latitudes and longitudes with the height of mounted antenna dictated by functional requirements of the network. The availability of land which satisfies ideal installation conditions in urban areas is extremely limited giving no alternative but to adopt roof top towers (with marginal adjustment in position but not in height). In the present study, the seismic response of 4-leged angled section and 3-leged tubular section rooftop telecommunication tower has been studied under the effect of design spectrum from the Indian seismic code of practice for Zone-IV along with wind analysis as per IS 875 (Part 3) 1987. The analysis has been performed on tower located on the roof of host structure by varying positions and height of tower in SAP2000 software. The axial forces in rooftop tower, inter-story drift, stresses and torsional effect on host structure due to rooftop tower are considered as the main parameter for this study. The effect of flexibility of soil on host structure also been considered to study the design parameters with respect to fixed base.