2D microscale finite element modelling of seismic P-wave propagation in marine saturated sands to predict geotechnical parameters

This paper demonstrates that microscale 2D finite element modelling can accurately predict propagation of seismic P-waves through a medium of linear-elastic grains saturated with a viscous fluid. The model outputs correspond well with Biot’s equations for elastic wave propagation at frequencies relevant to offshore geophysical surveying in saturated porous media and allow for exploration of the effects of properties of individual grains (e.g. mass, shear moduli, bulk moduli) and the properties of the granular sediment matrix geometry (e.g. porosity, grain size distribution) to be studied in relation to the seismic properties of the saturated media. In addition to validation of the model through several example granular sediment matrix geometries, initial sensitivity analyses for key grain parameters are provided. The micro finite element analysis also enables comparison of the relationships between seismic properties and geotechnical properties required for engineering design of infrastructure, which are known properties found via static tests with the same micro-scale finite element mesh.