PSI - Issue 84

Tommaso Pivetta et al. / Procedia Structural Integrity 84 (2026) 1286–1293 T. Pivetta et al. / Structural Integrity Procedia 00 (2026) 000–000

1288

3

Fig. 2. Bridge as-built drawings: deck cross-section, plan view, and elevation view.

Fig. 2). Each span consists of seven I-shaped prestressed concrete girders and three cross-beams, completed with a reinforced concrete slab. The girders are simply supported with Gerber joints at their ends. Each span has a net length of 33.70 m and a total width of 14.70 m. The first span of the bridge (on the left side in Fig. 2) was equipped with an SHM system, including accelerometers installed along the girders and inclinometers positioned at the girders ends and at the top of the piers. The accelerometers enabled the identification of the natural frequencies and mode shapes of the deck, providing the reference data for the calibration of the numerical model. 2.2. Experimental campaign The experimental campaign lasted a total of 2 hours and was carried out during the night in order to minimize the traffic disturbance, as the bridge was closed to transit. During the tests, two heavy vehicles were used: the first with a total weight of 44 tonnes (1 tonne = 1000 kg ≈ 10 kN) subdivided into five axles, and the second with a total weight of 108 tonnes, subdivided into nine axles. The vehicles crossed the bridge at different speeds (20 km/h, 50 km/h and 70 km/h) and along two main trajectories: centrally aligned and along a single traffic lane. The technical configurations of the vehicles are shown in Fig. 3, while the axle loads are summarized in Table 1.

a)

b)

Fig. 3. Heavy vehicle configurations: (a) 44 t and (b) 108 t.

Data acquired during the campaign consisted of acceleration and inclination measurements recorded at strategic locations of the bridge (e.g., at the girders ends, quarter span and midspan for the accelerometers; and at the girder ends and at the top of piers for the inclinometers). Fig. 4 presents an example of the signal acquired during the tests.

Table 1. Axle weights for the two heavy vehicles, expressed in tonnes.

Vehicle

Axle 01

Axle 02

Axle 03

Axle 04

Axle 05

Axle 06

Axle 07

Axle 08

Axle 09

44 tonnes 108 tonnes

7.00 8.50

13.00

8.00

8.00

8.00

-

-

-

-

8.50

13.00

13.00

13.00

13.00

13.00

13.00

13.00