Vulnerability assessment of cantilever earth-retaining walls along the Italian roadways

Abstract

The road network is the primary infrastructure for reaching earthquake-affected areas and bringing the necessary aid. Damage to components of the roadway network (for example, earth retaining structures) can have a significant impact on the movement of people and goods both during an emergency and in the long-term period. During past and recent earthquakes worldwide, several retaining structure failures were caused by the seismic action. In Italy, many earth-retaining walls are located in regions characterized by high seismic hazard. Therefore, the vulnerability assessment of these structures is of paramount importance for performing seismic risk analysis of the road network. Fragility curves represent a useful tool for estimating the seismic vulnerability of these typological structures. Novel sets of fragility functions for cantilever retaining structures, the most common earth retaining structures along the Italian roadway network, were built in this study using a numerical approach. Advanced simulations were carried out using real accelerograms as seismic input and adopting the usual T-shape structure and horizontal backfill configuration as models. Special effort was spent to identify the Intensity Measures (IMs) best correlated to the response of the object walls. To conclude, the proposed fragility curves can be effectively adopted for rapid assessment of earthquake-induced damage both during emergency management to provide the safest ways and also in the preparedness phase to identify proper countermeasures for seismic risk mitigation.