Virginia Tech Moss Arts Center
Monumental Stair Vibration Study
This research study was conducted by the VTL personnel to provide a better understanding of the dynamic behavior of monumental stairs subjected to occupants' loads.
The design architect for the Virginia Tech Moss Arts Center is Snohetta. The building houses two monumental steel stairs. The lower stair has a total length of 72 ft. -8 in., and the upper stair has a total length of 58 ft. -3 in. (both measured along the outer stringers). The lower stair is supported by a column located at the center of its landing, and the upper stair landing beam is also supported by a column. The largest unsupported portion of the stairs is about 36 ft.
A series of vibration tests on the stairs were conducted. The measured first mode natural frequencies of the upper and lower stairs are 7.6 Hz and 11.5 Hz, respectively. Large groups of people ascended and descended the stair at different speeds and the generated vibration were recorded. The analysis of these data and further studies are still on-going.