An Empirical Function to Predict the Liquefaction-Induced Uplift of Circular Tunnels: Fid-Bau Portal

An Empirical Function to Predict the Liquefaction-Induced Uplift of Circular Tunnels

Seyedi, Mohsen

Tunnels buried in liquefiable soils are prone to liquefaction-induced uplift damage during strong earthquakes. Studying the parameters that affect the liquefaction-induced uplift of tunnels is crucial for enhancing the seismic resilience of tunnels, minimizing potential damage, and ensuring the safety of critical infrastructure during strong earthquakes. This study investigates the effects of tunnel diameter (D), burial depth (H), and amplitude of input shaking at the base of the soil layer (a_max) on the liquefaction-induced uplift of circular tunnels using numerical simulation. A comprehensive parametric study was conducted to investigate the effect of the H/D ratio and the value of a_max on the dynamic responses, such as uplifts and internal forces in the lining of the tunnel. Using the numerical results, an empirical function was proposed to estimate the liquefaction-induced uplift of circular tunnels buried in liquefiable, loose soils. Finally, the results predicted by the proposed function were compared with those of a shaking table test and a centrifuge experiment. It has been demonstrated that the burial depth of a tunnel has the greatest impact on its seismic performance. Under identical input motion, increasing the burial depth of a tunnel with a 5-m diameter from 5 to 10 m resulted in a 270% increase in uplift and increased the internal forces in the tunnel lining, noticeably.