A Study on the Development of the Seismic Fragility Functions of the High Speed Railway Tunnels in use

Abstract

In this study, the staged seismic performance evaluations were conducted to the 91 high speed railway tunnels in use for checking whether to comply with the recent design criteria or not. In addition, the seismic fragility functions of the tunnels were developed to allow the probabilistic risk assessment. The results of the staged seismic performance evaluations which consist of a preliminary assessment and a detailed assessment, show that the tunnels comply with the recent design criteria. With reference to the results of previous studies, a form of the proposed seismic fragility functions was set as a log-normal distribution by PGA, and the parameters of the functions were determined by using the probability of damage for the design PGA level. The seismic fragility functions were developed for each types (Cut & Cover, NATM) of tunnels. The seismic fragility functions from this study and the existing research results (FEMA, 2004) were compared to evaluate the seismic performance level of the tunnels, as a result the tunnels of this study were relatively superior to the ASSM tunnels on the seismic performance.

Seismic Vulnerability Assessment in Tunnels: A Review

“…Finally, the seismic vulnerability curve of the tunnel was obtained by applying the mathematical method of maximum likelihood estimation (MLE) [15]; Kim conducted seismic performance evaluation on the classification of Jinfu high-speed railway tunnels and established a seismic vulnerability curve for probabilistic risk assessment. The comparison showed that the seismic performance of the hidden excavation method tunnel was better than that of the cover excavation method tunnel, and the probability of each damage level was relatively low [16]; Mayoral conducted threedimensional finite difference nonlinear analysis using FLAC3D to obtain the seismic response of tunnel shafts under increasing seismic intensity, and established their seismic vulnerability curves [17]; Andreotti proposed a new cumulative damage index for deep buried tunnels to evaluate the degradation failure behavior of reinforced concrete under cyclic loading, and based on plastic concentration theory and multiple two-dimensional incremental dynamic analyses, simulated the seismic cumulative damage of tunnel lining [18].…”

Developments in Seismic Vulnerability Assessment of Tunnels and Underground Structures

“…Kim et al [50] developed PGA-based fragility curves for NATM tunnels, analysing numerically (by means of dynamic time-history analyses) the fragility of 91 newly built tunnels in Korea. Fragility curves were derived for distinct damage states, using the exceedance of capacity of the liners for the definition of the damage state thresholds.…”

“…In addition to rock tunnels, Kim et al [50] developed PGA-based fragility curves for cut and cover tunnels, numerically analysing the fragility of newly built tunnels in Korea.…”