Aeroelastic testing of monopole mounted on a high-rise building under atmospheric boundary layer wind

Modern architectural designs of high-rise buildings have evolved to comprise a higher pinnacle to further increase the building height or to incorporate telecommunication devices by utilizing roof-mounted structures such as monopoles or lattice towers. However, due to their height and flexibility, the susceptibility of roof-mounted structures to wind-induced vibrations becomes a concern, especially when it couples with building-associated vibrations. Prior studies have addressed the wind-induced response of either high-rise buildings solely or ground-mounted telecommunication structures, leaving a gap in understanding the behavior of their roof-mounted replicas. To that end, this paper investigates the dynamic response of roof-mounted monopoles through an aeroelastic wind testing campaign. A 2-DOF aeroelastic model with a geometric scaling of 1:150 was developed to represent a 166-m high-rise building with a 40-m tall hollow-sectioned monopole mounted on the rooftop. This paper considers varying wind speeds and structural damping conditions of the supporting building. Results indicate that wind-induced vibrations of the building significantly amplify the response of the roof-mounted monopole for different Scruton numbers. Additionally, the vibrational characteristics of the building may be reflected in the monopole's response, inducing an amplification in the response. The across-wind response of the building greatly influences the dynamic response of roof-mounted monopoles, an effect that current standards overlook. The findings suggest maximum magnification factors of 8.83 based on the root-mean-square (RMS) of wind forces acting on the tip of the monopole in the across-wind direction. Furthermore, vortex-shedding effects associated with the building cause excessive vibration in the monopole, particularly at low Scruton numbers. This study lays the foundation for bridging the existing gap in the literature and provides foundational insights into wind-induced dynamics of roof-mounted monopoles that potentially inform future advancements in building codes and standards.