Art Gallery of Ontario, Toronto / Gehry Partners, LLP

situation:

In 2002, the Art Gallery of Ontario embarked on an expansion and redesign of their building, led by the world-renowned architect Frank Gehry.

The plans added a ballroom, restaurant and more exhibition space. Storeys were added above, but structurally independent from, the existing building. The AGO reopened in 2008.

assessment:

Aercoustics was retained as part of the design team in 2004 to provide the acoustical and specialized vibration engineering including room acoustics, sound isolation, and noise and vibration controls for the base building’s equipment.

During the design phase, the team was concerned about excessive floor vibrations caused by guests walking in the gallery exhibit areas or dancing in the ballroom. The added upper floors were lighter and had a longer span than the floors of the existing AGO building. This could have a detrimental effect on art objects and be disruptive to other guests.

solution:

Aercoustics conducted a literature search of artwork sensitivity to vibrations. Appropriate floor vibration criteria were developed using the findings of this search, engineering standards for human sensitivity to floor vibrations and Aercoustics’ vast experience.

We then created a computer model of the new building structure to aid in the prediction of floor vibration levels generated by walking and compared it against the sensitivity criteria. Simulation runs of people walking were performed and it was determined not to be a problem.

However, simulation runs of dancing in the third floor ballroom predicted rhythmic floor vibrations into the fourth and fifth floor gallery spaces.

Aercoustics developed and analyzed several solutions. The best was to use Tuned Mass Dampers (TMDs). One TMD would be installed on the underside of each of the fourth and fifth floors – each effectively absorbs the vibration energy and reduces it to imperceptible levels. Aercoustics provided the physical parameters and specifications for the TMDs.

results:

Floor vibration testing was conducted and confirmed that the TMDs effectively provide the vibration mitigation required for this world class facility.