A Novel Approach for Evaluating Seismic Performance of Frame-Type Underground Structures

This paper examines the seismic performance evaluation methodology for underground structures. Through analysis of seismic damage and failure characteristics of underground structures, this study proposes a novel evaluation approach for frame-type underground structures based on the sectional curvature deformation indicator of structural components. The research establishes a classification system for seismic performance levels with corresponding state descriptions. A comprehensive seismic vulnerability analysis is conducted on a typical two-story-three-span station structure, generating vulnerability curves based on the proposed indicator. For comparison with traditional methods, vulnerability curves are also developed using the interstory displacement angle indicator. The comparison results indicate that relying solely on interstory displacement angle provides an insufficient assessment of the seismic performance of underground structures. The proposed methodology more effectively captures the influence of critical parameters, such as the axial compression ratio of interior columns, on overall seismic performance. This methodology demonstrates robust applicability across diverse frame-type underground structures in practical engineering scenarios, enabling precise evaluation of their seismic performance.