2026 Volume 12 Issue 5 Pages 223-228
In this study, the dynamic stability assessment of underground structures under seismic loading is carried out by combining the back analysis of rock mechanical parameters with a case study of the Oya tuff underground quarry in Japan. The modulus of elasticity and Rayleigh damping coefficient of the Oya tuff were obtained by inversion of the field shock vibration test, and the FLAC3D three-dimensional numerical model was constructed to simulate the dynamic response under the action of the 2024 Ibaraki earthquake (M5.3). The results show that the deformation near the seismic wave input point is significant; the persistent stress concentration exists at the corner of the pillar base, which is easy to trigger plastic deformation. A dynamic stability assessment framework integrating the plastic zone ratio, displacement field and stress concentration factor is proposed to provide a theoretical basis for pillar foundation reinforcement and roof monitoring. The study verifies the reliability of the inversion parameters for seismic performance assessment of underground structures, which provides technical reference for similar projects.
