# A Theoretical Study on the Resilience Evaluation Method of Operational Road Tunnel Systems
## 5 Resilience Evaluation Method of Road Tunnel  
### Evaluation Method and Indexes  
The existing resilience evaluation methods mainly include the index system method and the network analysis method. The index system method is mainly applied to the resilience evaluation of a single system. In the study of urban resilience evaluation, [PERSON] [22] has developed a framework for assessing urban resilience. The resilience assessment framework mainly divides the indicators into four dimensions: health and wellbeing, economy and society, infrastructure and ecosystem, and leadership and strategy. On this basis, 52 primary indexes and 156 secondary indexes were constructed to evaluate urban resilience. The establishment of the index system can comprehensively analyze the influencing factors of resilience. [PERSON] [23] constructed the resilience evaluation index system for road tunnel construction. In this index system, the absorptivity resistance, adaptive learning ability, and recovery ability are taken as the first-level evaluation index. The second-level index is the specific system used to realize the above functions; however, in the absence of a large amount of supporting data, index weights and scores tend to be too subjective. The network analysis method is mainly applied to the resilience evaluation of road networks. Taking the road network in East China as the research object, [PERSON] [24] established the network topology model using counties and cities as nodes. The key nodes and key sections in the network are identified using computer simulation to evaluate the risk of the road network. The network established in this method is nondirective between nodes. This network analysis method is suitable for systems with multiple explicit nodes. The road tunnel system cannot construct such a nondirective network. The resilience evaluation method of road tunnels should be oriented to actual needs. If the evaluation only obtains a specific resilience value of highway tunnels, it can only have a general understanding of the resilience state of road tunnels. It cannot identify the pain points and weak links of the system in the prevention process of external disturbances. Such resilience evaluation methods lack practical utility; therefore, the resilience evaluation of road tunnels needs to analyze the critical path in the process of resisting external disturbances in detail, to point out the key nodes and important paths of the system. In order to meet the needs of the evaluation, a resilience evaluation method of road tunnel systems was constructed by combining the index system method with the network analysis. The five basic attributes of road tunnel resilience proposed in Section 3.2 were taken as primary evaluation indexes. A formula for calculating the subitem resilience value of road tunnels was proposed as follows:  
\[R_{i}=\omega_{r}R_{r}+\omega_{a}R_{a}+\omega_{s}R_{s}+\omega_{c}R_{c}+\omega_{ b}R_{b}\]  
where \(R_{i}\) is the value of road tunnel resilience for a single external disturbance, \(R_{r}\) is the resistibility value, \(R_{a}\) is the adaptability value, \(R_{s}\) is the responsiveness value, \(R_{c}\) is the recoverability value, \(R_{b}\) is the robustness capability value, \(\omega_{r}\) is the resistibility weight, \begin{table}
\begin{tabular}{c c} \hline \hline
**Basic Attributes of** & **Interpretation** \\
**Road Tunnel Resilience** & The ability of the road tunnel system to cope \\ \hline Resistibility & with “external disturbance” \\ Adaptability & The ability of the road tunnel system to adapt \\  & to “external disturbance” \\ Responsiveness & The ability of the road tunnel system to \\  & respond to “external disturbance” \\ Recuperability & The ability of the road tunnel system function \\  & to recover quickly \\ Robustness & The ability of the road tunnel system to recover \\  & stability after suffering “external disturbance” \\ \hline \hline \end{tabular}
\end{table} 
Table 2: The table of basic attributes of road tunnel resilience.