Tuned-Mass Damper Design - Our team documented its findings and recommendations in a Phase I report [PDF]. The tuned-mass damper (TMD) option was selected, and we designed three TMDs for the frame and performed structural dynamics analyses to verify they would achieve the vibration mitigation objective
Prototype Testing - The TMD components were fabricated by Johnston Products in Dallas, Texas per the design. We performed vibration tests on prototype TMDs at the fabricator's shop to identify the design option with the best combination of frequency and damping properties
In-Situ Performance - TMDs were installed under our oversight. We then measured the control room vibration to verify the performance objectives were met. The TMD design, testing, and performance details are documented in the Phase II report [PDF].
Vibration Problem- A prefabricated control room on a structural steel support frame swayed side-to-side. our firm performed asite vibration surveyand identified the cause as excitation of the very low-damped sway mode of the steel frame by ground-borne vibration