PSI - Issue 5

Pavel Ryjáček et al. / Procedia Structural Integrity 5 (2017) 1051 – 1056 Ryjacek/ Structural Integrity Procedia 00 (2017) 000 – 000

1055

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that all bearings behave and should be modeled as fixed bearings. The same behavior is valid for the evaluation of the frequencies from the micro-seismic vibrations. However, for the forced vibrations during train passing on the bridge, the movable bearings should be still used.

Fig. 5. The displacement in the bearings

1st

2nd

3rd

4th

Fig. 6. The first four mode shapes from analysis (left) and from the tests (right)

Table 2. Measured and calculated natural frequencies No. Natural frequencies calculated [Hz] Natural frequencies measured [Hz]

Difference - measured/ calculated frequency [%]

Mode shape description

1 2 3 4 5 6 7

1.72 2.22 2.79 3.64 3.92 5.00 5.43

1.81 2.47 2.78 4.06 4.56 5.63 x

-5.6

1 st lateral mode shape of the arch 1 st lateral bridge mode shape 1 st vertical bridge mode shape 2 nd horizontal arch mode shape

-11.4

0.4

-3.6

1 st torsional mode shape 2 nd vertical mode shape

8.7

-3.7

2 nd lateral bridge mode shape