If your doing a basic liquefaction assessment on Sandy soil with SPT or SCPT I don't see how you need finite element modelling at all. If your doing an advanced liquefaction assessment your probably better off using flac to model with UBC sand or PMSand or PMSilt material behaviours.
The first stage of site investigation is desktop and it informs the engineer of the anticipated subsurface conditions. By precluding the site investigation the design engineer cannot accept any responsibility for providing a safe and economical design.