Hazard identification and analysis of urban utility tunnels in China

•EPE model from perspective of energy works well in UUTs’ hazard identification.•UUTs probably have more serious consequences in the worst-case accident scenario.•UUTs do have significant advantages for active safety to minimize probabilities.•UUTs need to be clearly classified and coordinately developed with other facilities. With the rapid urbanization and development of China, urban utility tunnels (UUTs) that combine various city lifelines are developing quickly. However, along with the convenience brought by UUTs, these concentrated lifelines also create more potential hazards. To overcome the shortage of traditional hazard identifications and match the characteristics of UUTs, the EPE model (Energy transfer theory - Preliminary hazard analysis - Evolution tree) is proposed in this paper. Based on the EPE model, a series of well-organized hazard lists of UUTs are presented, including 189 hazards in 28 categories, covering common hazards, specific hazards and risks of multi-hazards of UUTs. Following the identification of worst-case accident scenarios, a comparison analysis of UUTs and traditional pipelines is performed. Moreover, several practical suggestions regarding long-term planning, durability, classification and regulation of UUTs are proposed. This research may be helpful to establish safer, more coordinated and efficient UUTs to facilitate city life.