6
M. D. Martínez-Rodrigo et al.
V (km/h)
a
x
L
@ =1.5 (m/s )
max
2
a
x
L
@ =1.5 (m/s )
max
2
V (km/h)
4.0 K p
2.0 K p
1.0 K p
0.5 K p
4.0 K b
2.0 K b
1.0 K b
0.5 K b
0.0 C b
2.0 C b
1.0 C b
0.5 C b
(a)
(c)
(b)
(d)
Fig. 5. Results from sensitivity analysis over track parameters
4 Experimental Validation
4.1 Experimental Campaign Description
In May 2019 the authors performed an experimental campaign on Old Guadiana Bridge
with the purpose of characterizing the structure and soil dynamic properties along with
the bridge dynamic response under railway traffic. As per the acquisition equipment, a
portable acquisition system LAN-XI of Brüel & Kjaer was used. The acquisition system
fed the sensors (accelerometers) and an instrumented impact hammer in the case of
the soil tests. It also performed the Analog/Digital conversion (A/D). The A/D was
carried out at a high sampling frequency that avoided aliasing effects using a low-pass
filter with a constant cut-off frequency. The sampling frequency was f s = 4096 Hz. The
acquisition equipment was connected to a laptop for data storage. Endevco model 86
piezoelectric accelerometers were used with a nominal sensitivity of 10 V/g and a lower
frequency limit of approximately 0.1 Hz. The acquisition system was configured to avoid
the sensors’ overload (Fig. 6).
From the dynamic characterization of the soil, which was carried out by the by
Spectral Analysis of Surface Waves test a rather stiff soil was identified with a shear
wave velocity higher than 250 m/s in the upper soil layer. The bridge response depends
on soil-structure interaction (SSI) and soil stratigraphy. However, due to the high soil
stiffness identified, in a first approach this effect is disregarded.
M. D. Martínez-Rodrigo et al.
V (km/h)
a
x
L
@ =1.5 (m/s )
max
2
a
x
L
@ =1.5 (m/s )
max
2
V (km/h)
4.0 K p
2.0 K p
1.0 K p
0.5 K p
4.0 K b
2.0 K b
1.0 K b
0.5 K b
0.0 C b
2.0 C b
1.0 C b
0.5 C b
(a)
(c)
(b)
(d)
Fig. 5. Results from sensitivity analysis over track parameters
4 Experimental Validation
4.1 Experimental Campaign Description
In May 2019 the authors performed an experimental campaign on Old Guadiana Bridge
with the purpose of characterizing the structure and soil dynamic properties along with
the bridge dynamic response under railway traffic. As per the acquisition equipment, a
portable acquisition system LAN-XI of Brüel & Kjaer was used. The acquisition system
fed the sensors (accelerometers) and an instrumented impact hammer in the case of
the soil tests. It also performed the Analog/Digital conversion (A/D). The A/D was
carried out at a high sampling frequency that avoided aliasing effects using a low-pass
filter with a constant cut-off frequency. The sampling frequency was f s = 4096 Hz. The
acquisition equipment was connected to a laptop for data storage. Endevco model 86
piezoelectric accelerometers were used with a nominal sensitivity of 10 V/g and a lower
frequency limit of approximately 0.1 Hz. The acquisition system was configured to avoid
the sensors’ overload (Fig. 6).
From the dynamic characterization of the soil, which was carried out by the by
Spectral Analysis of Surface Waves test a rather stiff soil was identified with a shear
wave velocity higher than 250 m/s in the upper soil layer. The bridge response depends
on soil-structure interaction (SSI) and soil stratigraphy. However, due to the high soil
stiffness identified, in a first approach this effect is disregarded.