Wind Effects and Dynamics Characteristics of Base-Isolated Building based on Full-scale measurement during Typhoons

Abstract

This paper presents analysis of wind-induced response of asymmetrical base-isolated building during the passage of Typhoon Roke 2011, Typhoon Guchol 2012 and a bomb cyclone strong-wind event on April 3, 2012. Dense array permanent monitoring system provides three-days continuous records of the building accelerations during the events. The building’s wind-induced responses reveal non-linear characteristics of natural frequencies, damping ratio and mode-shapes. Natural frequencies of fundamental modes decreased with the increase of amplitude of building’s acceleration. Frequency reductions during strong wind are shown to be related to deformation of isolators due to static wind force. Damping estimates of the fundamental modes were increased with increase of building’s accelerations, which is attributed to the increase in damping from isolators and dissipative energy devices. Shapes of the fundamental modes showed different behavior than that of earthquake-induced mode-shapes. Characteristics of the mode-shapes were also found to be depended on the wind speed.