PSI - Issue 64

Marco di Prisco et al. / Procedia Structural Integrity 64 (2024) 2133–2140 M. di Prisco, L. Radice, M. Colombo / Structural Integrity Procedia 00 (2019) 000 – 000

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(c)

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(a)

Figure 6. Structural section considered of the beam: case A (a), case B (b) and case C (c) - (red points = fully neglected rebars)

5. Load test A load tests has been performed on the bridge in order to verify its structural response when typical live loads are applied and to assess the reliability of the finite element models adopted for the safety verification. Four different trucks were used to apply the load; each truck had 4 axes, the average load of the truck was equal to 27.6 tons, while the average load applied on each single axis is respectively equal to 7.5, 5.5, 7.8 and 6.8 tons moving from the front to the back of the truck. Eighteen different loading phases were considered: the eleven ones corresponding to the loading conditions are described in terms of truck position in Figure 7, while the unloading ones are not depicted. During the tests, the vertical displacement of the bridge was measured at the mid-span on both the bridge sides and at the third of the span in the middle by means of 4 wire displacement transducers (d1-4 in Figure 8). Additional displacement transducers were used to measure the displacement at the support in four position (d5-8 in Figure 8) and the longitudinal deformation of the bridge at the intrados of the beams (COD in Figure 8) and at the extrados of the slab (ε sup ). The main results (vertical displacement d1 d2 and longitudinal deformation ε 1,inf ) of the load tests are represented in Figure 9, where they are also compared with the prediction of the Finite Element Model for all the load cases investigated. Model 01 overestimate the bridge deformation, while it can be observed that Model 02 provides a reliable prediction of the bridge displacements especially when the maximum load is applied over the bridge.

Figure 7. Truck position at different load steps during the structural acceptance test