PSI - Issue 62

Giovanna Pappalardo et al. / Procedia Structural Integrity 62 (2024) 460–467 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 4. (a) Exploded and overall view of the bridge (strengthened configuration), and loading scenarios corresponding to the (b) unstrengthened and (c) strengthened configurations.

The simulation of the interaction between the landslide and the structure of the bridge is here simulated by means of an equivalent triangular load distribution    d (being d the vertical distance of the generic point from the surface of the terrain) applied to the uphill lateral surface of the bridge, adopting for the landslide a sandy-clay soil with a specific weight of  =20 kN/m³ (Figure 4b-c). More precisely, after applying the self-weight, for each configuration 11 different load scenarios were considered corresponding to as many levels of the terrain against the bridge ( H t ). It is worth noting that the effects of possible horizontal settlements of the foundations associated with the landslide motion, have not been analyzed in this study and should be the object of further future investigations.

(a)

(b)

Fig. 5. (a) Lateral displacements of the central pier of the bridge considering the unstrengthened (dashed lines) and strengthened (solid lines) configurations, and (b) lateral displacement u at the top of the central pier for different levels Ht of the terrain.

The profile of the lateral displacement u(z) of the central pier normalized by height of the central pier ( H =6.08 m) are represented in Figure 5a, where z (0 ≤ z ≤ H ) represents the vertical position of a generic point from the base of the foundation; a quasi-linear trend of the lateral displacements can be observed. As expected, larger values of u(z) correspond to higher level H t of the terrain. Although in the strengthened configuration the contact surface between landslide and bridge is larger, the stiffening effect of the reinforcing concrete rings strongly limits the displacement; more precisely, in correspondence of the most severe loading scenario ( H t = H ), u = max( u ( z )) = 21.15 mm, u/H =0.35%,