2.1 Construction of the bridge The bridge was built by using the free cantilever method
that is most commonly used for cable stayed bridges.
The construction stage-10 can be seen in Fig. 2 with a can-
tilever length of 209.40 m. Despite the fact, that the TMDs
were tuned with respect to the dynamic properties of the
completed bridge, the dampers were already erected and
activated during the construction stages in order to avoid
VIV prior to the deck closure.
2.2 Monitoring system on the bridge Monitoring system on structures are widely used  and
was also utilized considering the slenderness of this unique
bridge. The dynamic response of the Komárom Bridge as
well as the wind velocity were monitored simultaneously
by using sensors during the most critical construction
period. The sensor positions at the cross section can be
seen in Fig. 3. The wind velocity U and direction α were
recorded on both sides of the stiffening girder by using
sensors type Vaisala WINDCAP Ultrasonic Wind Sensor
WXT532 mounted onto high steel masts. The accelera-
tion sensors HBM B12 were installed to the cross sections
at the TMD location. The vertical accelerometers were
fixed to the top of the moving mass of the TMD (A TMD ) as
well as to the bridge deck section (A bridge ). Thus, the ver-
tical vibration of the bridge deck and the TMD could be
measured at the same time. As the length of the stiffen-
ing girder changed during the construction, the sensors
Fig. 2 Free cantilever of the bridge (courtesy of Pont-TERV Ltd.)
Fig. 3 Sensor positioning at the cross section
Fig. 1 Bridge deck with the designer team (courtesy of Pont-TERV Ltd.)
Szabó et al.
Period. Polytech. Civ. Eng.
were repositioned (at one time only) in order to be closer
to the end of the cantilever. Sampling rate for the wind
sensors was 1 Hz, while that for the acceleration sensors
was 20 Hz. The QuantumX MX840B universal measuring
amplifier, the UPS, the PC for the data collection and the
GSM communication were placed in a sealed box under-
neath the deck, near the TMD elements.