Effcts of 2-D irregular seafloor topography on undersea ground motion

The effects of seafloor topography on undersea ground motion is discussed in this paper. And a study on two-dimensional problems is done by finite element techniques. The fluid-soil coupling response computations of the system composed of sea water and seabed soil excited by base-rock shaking are fulfilled for the cases of convex and concave seafloor topography with differ- ent sea depths. Using the parameter analysis method the basic knowledge relevant to the problem above is gained:(1) the seismic response of higher place of seabed is greater than that of the lower place of seabed, and the response of the concave angular region between the higher place and the lower one is the smallest;(2)the seismic response of seabed becomes smaller for the convex case when the depth of sea water increases, and this phenomenon is not obvious for the concave seafloor to- pography. The geometric models of the problem of irregular seafloor topography are symmetrical. And the boundary conditions of the computations, especially those of the sea water portion are givien.