Assessing the effect of physical and social parameters on seismic risk of urban transportation networks

Abstract

In this paper, a comprehensive model is presented to assess the seismic risk of urban transportation networks. Hazard, vulnerability, response capacity and functional components are considered in the proposed model to estimate the risk index of transportation network at each urban zone. The hazard index accounts for both direct and indirect hazards, such as ground motion, landslide and fire. The vulnerability index is evaluated using physical elements (such as bridges, tunnels and pavement) as well as social factors (such as population density and percentage of casualties). The response capacity index is assessed based on the preparedness of response teams and availability of tools and equipment. The functional components comprise physical parameters related to road topology and characteristics, social parameters and the intelligent transportation system (ITS). The proposed model was tested in district 4 of the city of Qom in Iran to estimate the seismic risk level based on local conditions. The effectiveness of short-to long-term interventions for risk reduction also were assessed. The results indicated that road widening and development of emergency transportation network, reducing the risk of landslides and improving the ITS had considerable effects on risk reduction in the study area that can be implemented by long-to short-term interventions. The proposed model provides a practical tool for decision makers to assess and reduce the seismic risk of transportation networks.