Modelling liquefaction-induced building damage in earthquake loss estimation

The assessment of building damage caused by liquefaction-induced ground deformations requires the definition of building capacity and vulnerability as a function of the demand, as well as damage scales to describe the state of the damaged building. This paper presents a framework for resolving these issues within the context of earthquake loss estimations, where large variations in building stock and ground conditions must be considered. The principal modes of building response to both uniform and differential ground movements are discussed and the uncertainties in their evaluation are highlighted. A unified damage scale is proposed for use in both reconnaissance and assessment of all modes of building damage, including ‘rigid body’ response of structures on stiff foundations to uniform or differential ground movements. The interaction of ground shaking and liquefaction in the context of induced structural damage is also briefly considered. The paper raises important aspects of earthquake loss estimations in regions of liquefaction potential, which remain relatively poorly defined at present.