A study on performance-based evaluation system for NATM tunnels in use: development of evaluation model and validation

In a performance-based evaluation of structures in use, the current performance is assessed by summing up the weighting of the evaluation indices for each performance. In this study, to suggest a performance-based evaluation technique for NATM tunnels in use, the performance evaluation indices were derived by examining the characteristics and similarities of each index developed from previous study. The weighting of the evaluation indices was derived by calculating the relative importance of each evaluation indices from the AHP analysis. In order to develop a quantitative evaluation model, grading criteria for each performance index was derived through literature review, and performance evaluation tables for road and railway tunnels were presented. In order to verify the significance of the proposed performance evaluation model, the correlation analysis was performed between each evaluation index and the final evaluation result. In the correlation analysis, the survey data measured through precision safety diagnosis in the tunnel in use was applied. It may be said that the proposed evaluation indices, weighting, criteria and evaluation models for tunnels in use can be applied to the performance-based maintenance system of tunnels.