Strategies for the Assessment of Risk induced by Seismic Liquefaction on Road Networks

Seismic risk analysis and management of civil infrastructure systems has undergone an increasing interest among
researchers in the recent past. Different methods and approaches have been proposed mainly dealing with the
earthquake response of buildings and lifelines. Concerning transportation networks, most of the efforts focuses on
the response of bridge stocks to specific earthquake scenarios, but very few examples exist examining the
response of transportation networks as a whole. In particular, methods taking into account local site effects
induced by liquefaction of the foundation soil are not developed yet. In this paper a novel framework is proposed
to estimate the risk given by liquefaction on a road network within the more general EU project Liquefact. The
study combines geotechnical analyses and the assessment of the traffic conditions to define hazard, vulnerability
and exposure of the transportation network. The methodology has been applied to a rural area located in the
district of Terre del Reno (Emilia Romagna, Italy) struck in 2012 by a seismic sequence that produced extensive
liquefaction. The micro-zonation of liquefaction potential and the modelling of the transportation network are
coupled to assess risk and identify mitigation strategies.