National-scale infrastructure network exposure to liquefaction using geospatial models

抄録

Liquefaction hazard maps are a useful resource to help estimate the exposure and potential liquefaction-induced damage to the built environment. The most robust approach for the development of these maps is through the use of in-situ investigation data and simplified liquefaction evaluation procedures. When infrastructure networks are the focus of assessment, this method can be expensive and labour-intensive due to the large geospatial extent of these networks and the large number of investigation data required to provide good coverage. In these cases, geospatial methods can be used as an alternative approach. This paper focusses on the assessment of the exposure of New Zealand’s transportation (rail, state highways, and bridges) and power transmission networks to liquefaction, using geospatial liquefaction susceptibility methods. This approach has enabled the initial quantification of national exposure across each network for different liquefaction susceptibility categories, demonstrating that transportation systems are situated in areas that are more susceptible to liquefaction compared to power transmission facilities. To identify areas of high risk in terms of liquefaction induced damage, susceptibility needs to be linked with the seismic hazard across the country; this is the focus of the next step of this research. The criticality or significance of infrastructure should also be considered as part of this process to better quantify the impact of damage to the wider economy and society. This includes the modelling of other infrastructure networks, such as local roads, and the analysis of links between networks and areas of interest, such as populated places and sea ports.