WAPRO · Wave Propagation in Anisotropic Soil Strata Resting on a Poroelastic Half-plane by the BEM

The research subject under investigation is synthesis of artificial seismograms and of their corresponding response spectra on the free surface of non-horizontal soil strata exhibiting anisotropy and resting on a poroelastic half-plane through which propagate upward-moving seismic signals. Three basic steps are identified in this research work, namely (a) analytical solution of seismic wave propagation in a water-saturated, poroelastic half-plane; (b) formulation of the elastodynamic problem for wave propagation in laterally varying, anisotropic soil strata with free-field motion coming from the supporting poroelastic half-plane; (c) formulation and numerical implementation of a boundary integral equation method (BIEM) solution of the boundary-value problem corresponding to non-horizontal soil deposits in welded contact with the supporting half-plane and in the presence of a free-surface. In all cases, conditions of plane strain are assumed to hold, while all dynamic disturbances are of the time-harmonic type with transient behavior reconstituted through Fourier synthesis. The novelty in the proposed work lies in combining the anisotropic material model with lateral inhomogeneity in the soil deposits. Furthermore, the filtering of seismic signals through a poroelastic half-plane and their subsequent introduction to the overlying soil deposits is also considered novel, given that that existing, classical formulations pre-suppose an elastic, homogeneous and isotropic soil structure with discrete horizontal layers as the reference mechanical model. Additionally benefits will accrue from the development of efficient software based on the BIEM that will be validated against benchmark problems and then used for the synthesis of realistic seismic scenarios in geological areas of the wider Greece / Bulgaria region.