# Research on an Index System for the Earthquake Disaster Resistance Capability of Highway Tunnels
## 1 Introduction  
Earthquake disasters have occurred frequently in China in recent years, especially in the central and western regions, where many earthquakes with high seismic magnitudes have occurred. As a result, some highway tunnels in earthquake areas have damaged tunnel structures due to their insufficient seismic capability [1; 2; 3; 4; 5; 6; 7], resulting in traffic obstructions and even personal and property losses. Therefore, it is necessary to evaluate the earthquake resistance capability of highway tunnels to enable relevant construction companies to prepare for advanced prevention in operation and maintenance, and the most important step in this process is to establish an index system for the earthquake disaster resistance capability of highway tunnels. At present, scholars have carried out relevant research on the seismic damage impact factors, evaluation indices and methods of structural safety of highway tunnels. [PERSON] [8] established an index system for the seismic safety evaluation of mountain tunnels that includes more than 10 factors, such as the surrounding rock classification, unfavorable geology, geometric characteristics of the tunnel, seismic magnitudes and stress state of the tunnel lining. [PERSON], [PERSON] et al. [9] summarized and analyzed the establishedseismic performance parameters and, based on damage mechanics and experimental results, proposed the interlayer displacement angle as the seismic performance index of structures. [PERSON] et al. [10] summarized seismic damage factors, geological factors and structural factors as the main factors of earthquake disasters at tunnel portal sections through the statistical analysis of seismic damage data from portal sections of mountain tunnels during the Wenchuan Earthquake. [PERSON] et al. [11] evaluated the seismic capability of a tunnel in an earthquake area based on seismic damage data from a highway tunnel during the Wenchuan Earthquake through three factors: seismic intensity, lithology of the surrounding rock and fault features. [PERSON] et al. [12] established an evaluation grade index system for the damage of existing tunnel lining structures by starting with 13 independent factors of the damage to the lining structure of existing tunnels from the three aspects of engineering construction, the natural environment and engineering geology. [PERSON] [13] described the reasons and influencing factors of the construction of a safety evaluation management system for the current service status of highway tunnels, listed the damage problems existing in tunnel operation and, finally, determined the safety evaluation index of highway tunnels according to their composition and structure. [PERSON] et al. [14] summarized the main damage to the structural health of operational tunnels and the corresponding structural health evaluation indices of operational tunnel structures applicable to actual engineering projects. All these studies provided good methods and ideas for the construction of an index system for the earthquake disaster resistance capability of highway tunnels. However, the types of influencing factors considered in the evaluation index of earthquake disaster resistance capability are limited and cannot comprehensively reflect the earthquake disaster resistance capability of highway tunnels. This paper will conduct detailed investigations and statistics on highway tunnel seismic damage accidents during the operation period; analyze the scenes of seismic damage accidents of highway tunnels; use the fault tree analysis (FTA) model to identify the damage-causing factors and combine the industrial standards, specifications and research results related to the earthquake disaster resistance capability of highway tunnels, starting from three aspects: engineering geologic factors, tunnel structural factors and operation management factors.