Based on Fourier integral transformation and virtual work principle, a numerical analysis of the scaled boundary finite-element method in frequency-wave domain for the dynamic response of the elastic half-space to a moving load is proposed in this paper. With the application of double Fourier integral transformation from the time to frequency and space to wave-numbers, the elastodynamical governing equations of the half-space in the frequency-wave domain are derived. A scaled transformation in coordinates is performed and the FE discretization is performed along the circumferential direction of the tunnel, and thus the formulation of the scaled boundary finite element method in the frequency-wave domain is derived by virtual work principle. Then, the elastodynamical stiffness is transformed into a system of linear first-order ordinary differential equations. According to the proceeding of the proposed method demonstrates high efficiency and accuracy in dealing with the dynamic response of the subway tunnel embedded in the elastic half-space subjected to a moving load. Numerical results are presented to show that the vibration response of the elastic half-space increases with the increase of the speed of the moving load, especially when the load speed gets close to the shear wave velocity. It also shows that the dynamic response of the surface of the half space increases dramatically with the vibration wave propagating to the soil surface, which increases the risk of structural damage to the tunnel or any overlying structure. Also, compared with the vertical vibration of the elastic half-space, the speed of the horizontal vibration attenuation along the longitudinal axis of the subway tunnel is slower. © 2017, Nanjing Univ. of Aeronautics an Astronautics. All right reserved.
