In this study, an efficient dynamic analysis method of building structures for subway transit loading is developed. Building structure is modeled using a condensed analysis model for vertical vibration, for the analysis of vertical vibration, which is the principal component of the subway loading.
The dynamic analysis of structures including soil-structure interaction effect is performed both in the frequency and time domains. A separate analysis method is proposed using dynamic stiffness matrix for the soil-structure interface degrees of freedom. The dynamic stiffness of soil is evaluated by the finite element method incorporating infinite elements for the radiation effect. Equivalent subway forces are calculated at the soil-structure interface nodes. In the time domain analysis, the frequency-independent stiffness and damping of the soil are determined using a representative frequency and its corresponding soil impedance. A mode superposition method equipped with gauss-seidel iteration technique is presented. Example analysis is carried out for a structure embedded into a layered soil medium.