Risk assessment and loss estimation of urban built environments exposed to UVCE from off-site gasoline transport incidents

Abstract

The increasing gasoline consumption in India has led to a surge in off-site gasoline transportation, heightening the risk of spills triggering Unconfined Vapor Cloud Explosions (UVCE). Such incidents pose significant threats to the built environment, particularly in densely populated urban corridors. This study presents a systematic framework for assessing the physical vulnerability of urban structures to UVCE, employing a building prototype-based approach. The methodology integrates macro and micro-level assessments, considering building and neighborhood characteristics, structural integrity, and exposure levels to quantify potential damage. A deterministic blast overpressure analysis is conducted using the TNT equivalency method, mapping damage levels to building structures. The study employs an indicator-based approach to capture the effects of neighborhood configurations, architectural design, and structural attributes of buildings on blast overpressure which in turn alter the building damage. By defining standardized building prototypes, the framework estimates repair costs as a proxy for vulnerability, offering a detailed spatial assessment of at-risk areas. The model is applied to a high-density urban corridor in the Kolkata Metropolitan Area (KMA), where 1,979 buildings are surveyed, classified, and analyzed under a worst-case scenario, providing spatially visualized risk assessments. Findings reveal that neighborhood characteristics, architectural configurations, and structural integrity significantly influence vulnerability, highlighting high-risk zones requiring targeted interventions. The study underscores the need to integrate safety considerations into urban planning, infrastructure resilience, and emergency response strategies. By bridging risk assessment with urban development, this research provides policymakers, engineers, and emergency planners with actionable insights to mitigate UVCE risks in rapidly urbanizing environments.