Pile design for kinematic and inertial effects: a parameter study

The introduction of Eurocode 8 in Hungary presented new challenges in seismic design for geotechnical and structural engineers. During an earthquake, pile foundations must resist both the kinematic forces arising from the deformation of surrounding soil and the inertial effects due to the movement of the superstructure. The inertial effect is usually considered as a lateral load applied to the top of the pile, while kinematic effects are evaluated only in special cases. The evaluation criteria: (1) design ground acceleration >0,1g and (2) soil type D or worse; exist at many building sites in Hungary. Plaxis 3D software with HSSmall soil model was used to analyse the pile behaviour under a seismic event. The model was validated by comparing results to independent site response analyses and analytical equations estimating bending moment in the pile. A parametric study was then carried out to check the effects of mass at pile head and layer thickness on bending moments.