Upon having the construction of a new church near completion, walking induced vibration was perceived on a long span balcony. DEICON conducted on-site measurements and identified the first two natural frequencies of the balcony. In addition, the participating mass and the damping ratio of mode 1 of the balcony were evaluated.
DEICON designed and fabricated two tuned mass dampers for the balcony. Comparison of the measured balcony vibration without and with the TMD pointed to an excess of 5 fold increase in the damping of the first (target) mode of the structure, from 2% (without the TMD) to 11% (with the TMDs). Such an increase in damping lowered the walking induced vibration along the edge of the balcony by the same factor.