Seismic Response Analysis of Shield Tunnels Under Non-uniform Excitation in Soft Soil Areas

Underground rail transit, as an important part of urban public transportation, has a huge role in promoting the economic and social development of China, and its seismic safety is crucial in soft soil area. To improve the seismic design of subway tunnels, this paper employs numerical simulation to establish a refined model of large and long tunnels to study the seismic dynamic response of subway tunnels. By inputting Tianjin waves into the bottom part of the model, the seismic response of the soil and tunnel system under non-uniform excitation is investigated, and the differences between the response and that under uniform excitation are compared. The comparative analysis shows that the acceleration and velocity response of the soil and tunnel under non-uniform excitation, the relative tunnel displacement and the internal tunnel force are greater compared to the uniform excitation. The influence of the spatial effect of ground shaking should be properly considered when performing large-scale earthquake simulation calculations.