1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

The seismic performance assessment of an urban system can help raise awareness and improve a community’s preparedness for extreme earthquake events. Addressing this issue, the authors’ first attempt at a quantitative evaluation of a city’s performance in the event of an earthquake is presented in this paper. The assumed city model comprised of four main urban components (buildings, transportation infrastructure, social community, and open spaces) takes into consideration their relationships and interactions. A set of preliminary analyses on the test model were performed using the GIS tools and graph theory. The analysed model was generated based on the combination of real (city layout, buildings’ heights and footprints, road network configuration and length) and fictitious data (earthquake scenarios, structural fragility of the investigated building stock, the use of a building, etc.). In the main part of the study, several scenarios of possible earthquake events with various degrees of intensity and with different locations of damaged buildings were considered, and the assessment of a city’s performance in terms of connectivity and accessibility (the graph theory measure of global efficiency) was carried out. The impact of building debris on the roads as a result of the earthquake damage and/or the collapse of nearby buildings and their non-structural components was included in the analysis as well by applying the measure of a building’s impact radius and assessing the road traffic disruptions. Furthermore, certain practical results in relation to the analysed urban system were taken under observation and are discussed in the paper (travel time, affected population when considering the day-/night-time scenarios, etc.). The proposed framework has proven to be a viable tool for identifying network weaknesses and quantifying the loss of the city network functionality.