Structural strain estimates of a circular tunnel under seismic hazards

• Main Authors: Koike, Takeshi, Garciano, Lessandro Estelito O.
• Format: text
• Published: Animo Repository 2022
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/6115
• Institution: De La Salle University

This paper presents an analytical approach to estimate 3-dimensional structural strains of a circular tunnel under an earthquake ground motion. Theoretical expressions including not only the axial and bending strains in the longitudinal direction but also the cross-sectional strains of a tunnel are developed in order to assess the current seismic design methods. Furthermore, the theoretical derivation of the soil and tunnel interaction effect can provide the analytical expression of soil spring modulus. Numerical results suggest that the cross-sectional tunnel strains are dependent upon the tunnel liner's rigidity, so that the current design methods might overestimate the structural strains of the tunnel, especially having the liner's hard rigidity for the Level 2 earthquake in Japan.