A Numerical Based Parametric Study on Seismic Amplifications Due to Soft Deposits on Seabed

摘要

It is well known that seismic events at sea can lead to severe effects on marine facilities. A seismic event can generate amplifications due to local conditions of the place, that is, site effects. In this work, we show numerical results of seismic amplifications on the seabed where there is the presence of deposits formed by soft soils. We formulate the problem using an Indirect Boundary Element Method. In this formulation, we consider that the total field of displacements can be expressed in terms of an incident and another diffracted field. Specifically, the diffracted field is expressed in terms of Fredholm integral equations of second kind and zero order. This conceptualization can also be understood as the implementation of the Huygens Principle because the waves are constructed at the boundary from which they are irradiated. We study five geometries of soft deposits. In general, we found that P (compressional) waves can generate seismic amplifications of up to 45 times while SV (shear) waves cause amplifications up to 65 times.