Trevor Haskett
RWDI, Toronto

CASA II is a 185m tall condominium tower with a slenderness ratio of 10.3. This 56 storey tower is located in the urban centre of Toronto. During the structural design process, wind tunnel tests were undertaken that indicated the need for additional damping which would improve the serviceability of the upper floors of the tower. After examining various wind-induced motion mitigation options, the tower was fitted with three tuned sloshing dampers. One is located at the northern edge of the tower while the other two are stacked at the southern edge. The combined weight of water needed for the dampers is 173 tonne which changed the damping from 1.5% to 3.5% of critical!

While tuned sloshing dampers have been employed for some time, the truly unique feature of this project is the successful implementation of the performance monitoring of the CASA II Tuned Sloshing Damper (TSD) system.

The Full-Scale Long-Term Monitoring of the Sloshing Dampers installed in CASA II tower is the first one done in the world and so far we have collected invaluable data confirming that both the building and the damper are performing as per design.

This tour will include a presentation of the TSD design process, including the verification data that has been collected over the past three years. This will be followed by a tour of the dampers, including a view of the interior space where the sloshing energy dissipation devices (paddles) are visible.

We are very grateful to Cresford, Cresbuild and Crespro for giving us the opportunity to work on this unique project and for facilitating access to the dampers.