Seismic response of a motorway bridge founded in an active landslide: a case study

A twin girder 7-pier bridge, belonging to the "Egnatia" highway that has been facing numerous challenging geohazards, is built within an active landslide. Its seismic performance is investigated here through a comprehensive analysis of the interaction between bridge, foundation, and the precarious slope, which might affect 4 of the piers. The numerical 3D modeling considers in a realistic way the coupled effects of topography, soil nonlinearity, slope instability, and reinforced-concrete plasticity during seismic loading (kinematic and inertial). Alternative foundation schemes and slope stabilizing techniques are generically compared and evaluated. The aim is to develop a multi-hazard risk assessment platform that could facilitate the long-term management of motorways while shedding some light on the multi-hazard soil-structure interaction (MH-SSI).