A Model for Rapid Vulnerability Assessment of URM Buildings in Urban Centres Prone to Liquefaction

When two or more hazards occur in the same location or follow each other closely within a short timeframe, the infrastructure and the population can experience more severe consequences compared to when these hazards arise separately or in different locations. This research highlights the significance of accounting for liquefaction when assessing the vulnerability of infrastructure in earthquake-prone areas. Neglecting the possibility of liquefaction can lead to an underestimation of infrastructure susceptibility to damage. Therefore, it is important to consider both earthquake and liquefaction scenarios to accurately evaluate the vulnerability of infrastructure and take appropriate measures to mitigate potential damage. The literature review reveals a lack of research on seismic vulnerability assessment in urban centres when the effects of earthquakes and liquefaction induced by earthquakes are considered. Thus, it is important to formulate simple but robust methodologies for seismic evaluation in these urban areas, so that decision-makers may improve the land use plans. In this sense, this work will focus on proposing a simplified multi-hazard seismic vulnerability assessment approach for significant liquefaction-prone metropolitan areas exposed to earthquakes, with primarily unreinforced masonry residential buildings. The physical vulnerability of the residential buildings was appraised using an index-based method devised for structural masonry buildings to emphasize their likelihood of seismic damage. The proposed research comprises two key components: (i) a multi-hazard strategy tailored for areas susceptible to liquefaction, and (ii) a proposed schematic outlining a rapid method for assessing the seismic vulnerability of residential Unreinforced Masonry buildings, URM, in liquefaction-prone regions. This novel approach entails: (i) employing a multi-criteria decision-making to evaluate diverse factors and deliver a comprehensive assessment of a building's vulnerability, and (ii) conducting a multi-hazard interaction analysis through a probabilistic assessment of liquefaction hazards. Consequently, it provides users with a user-friendly and adaptable tool to integrate potentially liquefiable areas into a seismic risk model, which can be updated with damage information following an earthquake event.