# A Theoretical Study on the Resilience Evaluation Method of Operational Road Tunnel Systems
## 2 Literature Review  
Over the past few years, resilience has become a focal topic for transport infrastructure systems. As an important transportation infrastructure, road tunnels have been studied in depth by a large number of scholars. [PERSON] et al. [3] presented a detailed analysis and summary of the Port Authority of New York and New Jersey's pilot program for resilience management methodologies, which was applied to the Holland tunnel and the Port Authority Bus Terminal to evaluate their resilience to Superstorm Sandy-like flood hazards. The purpose of the pilot program was to solve the problem of resource allocation of critical infrastructure assets. [PERSON] et al. [4] used the defend-attacker-defender model to research the operational resilience of regional transportation systems. They utilized the major highway roads, bridges, and tunnels of the San Francisco Bay area as nodes to build a transportation network. This network was used to investigate the resilience to worst-case losses. [PERSON] et al. [5] proposed the concept of surrounding rock resilience of subway tunnels to effectively deal with the problem of instability of surrounding rock structures. They summarized the influencing factors of surrounding rock resilience of subway tunnels, including design, construction, and surrounding rock attributes, formed a surrounding rock resilience evaluation model with eight representative factors as the main evaluation indexes, and proposed an evaluation method of surrounding rock resilience of subway tunnels based on the Euclidean distance method. [PERSON] et al. [6] proposed the concepts of emergency resilience and the resilience ring by analyzing tunnel fire cases combined with existing resilience theories. They made a detailed analysis of the linkage operation mechanism of each tunnel subsystem during the whole process of fire occurrence and provided new ideas for tunnel disaster prevention and mitigation. [PERSON] et al. [7] believed that tunnel resilience had a great impact on the traffic efficiency of the road network. They proposed an ideal data collection framework to calculate the functional level value of road tunnels and then used data analysis to seek the relationship between tunnel design, operation, and tunnel resilience. [PERSON] et al. [8] put forward the concept of tunnel construction safety resilience. Taking resistance, adaptability, and resilience as the main aspects of construction resilience evaluation and fully considering the tunnel structure, geological conditions, emergency management, and other factors, they built a construction resilience evaluation model with nine representative factors as the main evaluation indexes. Based on the ideal fuzzy matter-element evaluation method, they proposed the weight of a specific evaluation index and the resilience grade of tunnel construction safety. [PERSON] et al. [9] built a resilience evaluation index system for tunnel construction emergency management, including 26 indexes. Using the order relation analysis method and the entropy weight method, the index weight was determined using the weighted average method, which effectively reduced the subjectivity of the evaluation. [PERSON] et al. [10] divided the engineering structure resilience design into four levels: single safety factor design, reliability design, robustness design, and restorability design. They summarized and analyzed the research progress in geotechnical and underground engineering fields in the above four levels. This research provides a reference for the resilience design theory and framework construction of geotechnical and underground engineering. [PERSON] et al. [11] proposed the idea of constructing an intelligent shield tunnel construction system based on the resilience theory to realize the intelligent shield tunnel construction in a resilient city. Their main idea was to use the resilience of materials and structure, combined with advanced intelligent technology, in order to realize the intelligent construction of the shield tunnel in a resilient city. [PERSON] et al.