Abstract: The nearfield oblique incident seismic waves might cause a catastrophe in submarine immersed tunnels. Thus, examining the dynamic response patterns of immersed tunnels and their shear keys under oblique incident earthquakes is imperative. First, the seismic wave is converted into the equivalent node force of the model boundary node based on the finite element method and the viscoelastic artificial boundary. This process establishes the threedimensional plane SV wave oblique incidence method based on wave theory and validates its accuracy through a halfspace example. Then, based on the seismic wave input method, a threedimensional refined finite element model of a soilimmersed tunnel is established using ABAQUS software. The influence of different SV wave incident angles on the dynamic response of an immersed tunnel and its shear key is studied. The results indicate the following: (1) When the incident angle of the SV wave is close to the critical value, the vertical and longitudinal responses of the tunnel reach the maximum. The horizontal response is inversely proportional to the incident angle. (2) The oblique incidence will cause asymmetric shear force in the symmetrical parts of the structure, changing the shearbearing ratio of the shear keys. (3) The root of the shear key is prone to tensile cracks, and the end angle might cause local damage due to compressive stress concentrations.

Key words:  , oblique incidence of SV wave, incidence angle, submarine immersed tunnel, soilimmersed tunnel model, shear key, seismic response