Toward a numerical-simulation-based liquefaction hazard assessment for urban regions using high-performance computing

Effective and efficient liquefaction hazard assessment is critical in making disaster mitigation plans for urban regions. In this paper, we present a numerical-simulation (NS)-based method for assessing urban-wide liquefaction hazard. The method includes an automatic modelling for individual sites and an application of high-performance computing (HPC) for efficient assessment. The feasibility of the method is demonstrated by conducting simulations for more than 10,000 individual sites in an urban region. The urban-wide assessment results depend on a pressure threshold of liquefaction occurrence and the dependence increases as the ground motion increases. A comparison with a conventional method using engineering indices (EI) shows a tendency of the EI-based method to predict a considerably greater number of liquefied sites than the proposed method. With the continuing improvement on numerical simulations and on computer efficiency, NS-based assessments can be regarded as promising alternatives to conventional EI-based methods for urban-wide liquefaction assessment. •For assessing urban-wide liquefaction hazard, a method based on a numerical simulation enhanced with HPC is proposed.•More than 10,000 sites in an urban region were assessed for liquefaction hazard, by applying the proposed method.•The urban-wide assessment depends on a pressure threshold, and the dependence increases as the ground motion increases.•A conventional method using Factor of Safety determined a much greater number of liquefied sites than the proposed method.•The prediction from the conventional method may indicate its tendency of overestimation of the liquefaction occurrence.