A hybrid multiresolution meshing technique for finite element three-dimensional earthquake ground motion modelling in basins including topography

This paper is concerned with a finite element method that uses hybrid meshes of multiresolution structured and unstructured meshes to simulate earthquake ground motion in large basins. While standard octree-based mesh methods use cubic elements and rely on mesh refinement to model topography, the present hybrid meshes use tetrahedral elements to model complicated layer interfaces and above-ground surfaces and to provide a transition between cubic elements of different sizes. The hybrid meshes avoid the step-like character inherent to the cubic meshes and the resulting concomitant loss of accuracy. Several numerical experiments of increasing complexity are carried out to verify and illustrate the proposed technique.