Automatic simulation techniques for 3D wave propagation in geological media
Final Report Abstract
This project was focused on the development of efficient simulation tools for the analysis of wave propagation problems in the soil. This is challenging, because real soil deposits can be highly heterogeneous and of very large extent at the same time. Novel numerical methods have been developed to address both these aspects. For heterogeneous soil, an automatic mesh generation approach based on digital image decomposition has been adapted to wave propagation. Imagebased analysis significantly reduced the manual effort of mesh generation for complex geometries. At the same, the resulting mesh has been tailored to speed up numerical analyses. Specifically, we are exploiting the similarity of cells in a balanced hierarchical mesh that consists of square or hexahedral elements only. To be able to model very large domains, we have developed an improved method to accurately capture radiation damping - a physical phenomenon by which energy is reduced in the domain of practical interest. This method allows us to keep the numerical model of the near field to the minimum size required from a practical point of view. Specifically, the scaled boundary finite element method is employed - a semi-analytical method that captures radiation damping rigorously. We propose an acceleration unit-impulse response-based explicit time stepping scheme for the solution of the equations of motion of a finite soil domain. These developments will in the mid-term contribute to facilitating three-dimensional analysis of soil-structure interaction problems, such as the seismic analysis of high dams or ultrasound-based geological exploration with the aim of finding resources or underground objects.
Publications
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Efficient simulation of waves in heterogeneous domains using the scaled boundary finite element method. PAMM, 22(1).
Nattoji-Shara, Sharath; Birk, Carolin & Gravenkamp, Hauke
