Full-scale monitoring of a tall, slender building with viscoelastic coupling dampers

Tall, slender buildings are sensitive to dynamic vibrations caused by wind, and occupant motion perception may be a critical design parameter. A method to control dynamic vibrations is to increase the damping characteristics of the structure, which may be accomplished using a supplemental damping system. A novel configuration for implementing solid viscoelastic damping in tall buildings, the Viscoelastic Coupling Damper (VCD), was implemented in a tall, slender building in downtown Toronto. The VCDs were designed to provide supplemental damping in the first and third modes of vibration to improve occupant comfort. This building was the subject of a year-long monitoring program where output-only system identification algorithms were applied to track the evolution of the dynamic properties through the construction of the building. Larger amplitude wind events occurred during the program, including an event with large insured losses in Ontario, allowing for the tracking of amplitude-dependent properties. The effect of the VCD system was assessed, and calibrated finite-element models were constructed with reference to the experimental results. It was found that amplitude-dependent trends were observed for the natural frequency, damping ratio, and the global movement of the building relative to the shear deformation in the VCD. It was also found that the VCDs provided the targeted supplemental damping of 0.9 % in the first and third modes, with a total damping in the building exceeding 2.5 % at larger amplitudes observed during a large wind loading event. The measured natural frequency of the first three modes of vibration and the local damper response matched the calibrated finite element models well. • Full-scale monitoring of a 200 m tall building. • Insights into the amplitude dependence of frequency and damping in tall buildings. • Confirmation of the levels of added damping provided by a novel passive supplemental damping system. • Insights into the relationship between global vibrations and the local deformations.