Earthquakes pose significant challenges to the stability and integrity of underground constructions, making an in-depth assessment crucial for enhancing structural resilience. The seismic effects on tunnels within varied rock mass qualities remain a critical concern in engineering practice. Understanding the impact of earthquakes on different rock qualities is imperative for ensuring structural integrity and safety. This study examines the impact of earthquakes on underground structures in varying rock mass qualities (Q) using numerical analysis. The study employs a finite element model to simulate the behavior of underground structures under seismic loading. The model considers the interaction between the structure and the surrounding rock mass, accounting for the influence of rock mass quality on the structural response. The study’s findings reveal that the seismic response of underground structures is strongly influenced by rock mass quality. Structures in lower quality rock masses (lower Q values) experience higher stress levels and deformations compared to those in higher quality rock masses. These findings provide valuable insights into the seismic vulnerability of underground structures and emphasize the importance of considering rock mass quality in the design and construction of such structures in earthquake-prone regions.