A comparison of linear and nonlinear seismic tunnel-ground interaction analyses

Abstract

In order to study the effects of a seismically induced tunnel-ground interaction, two-dimensional numerical analyses are performed using the sofware ANSYS. The study employs a coupled beam-spring model subjected to earthquake loading that is simulated under pure shear conditions and determined by a free-field ground-response analysis using the code EERA. The properties of the soil material are considered as both linear and nonlinear. The results obtained by linear dynamic analyses are compared with state-of-practice analytical elastic solutions. A comparison of the results of both linear and nonlinear analyses is also performed, and significant differences, as well as important factors influencing the tunnel-ground interaction f or both cases, are evaluated.