Analysis on the nonlinear dynamic soil-metro tunnel interaction in thick-soft site-displacement and acceleration response

Underground tunnels are usually considered to have good earthquake resistant behaviors. But as far as those earthquake damages of underground pipelines are concerned, underground tunnels can be damaged severely by the large relative distortion of surrounding soil layers. Accordingly, earthquake resistant behaviors of underground tunnels must be studied in detail. By considering the characteristics of soft soils in Nanjing, a representative soft site is selected as the groundwork of tunnels. By using ABAQUS finite-element software, the nonlinear dynamic soil-metro tunnel interaction is modeled by finite-element. The displacement and acceleration response of tunnels buried in three different depths are analyzed respectively. Results show that the relative displacement between the top and bottom of tunnels buried in soft site is very large. At the same time, the soil-structure interaction has a great effect on the displacement responses of tunnels.