During earthquakes seismic waves crossing through soft soil can lead to significant curvatures on pile foundations, which in turn lead to significant bending moments. These bending moments are commonly named "kinematic bending moments" to be distinguished from the "inertial bending moments" due to horizontal forces transferred from superstructures to pile heads. Approaches to carefully evaluate inertial bending moments have been developed worldwide ; on the contrary, up until now different simplified approaches have only led to different evaluations of the kinematic bending moments on pile foundations. Thus, the evaluation of kinematic bending moments is still questionable. Nevertheless, the European technical code EC8 and the new Italian technical code, D.M. 14/01/2008, underline the importance, in the geotechnical and structural design of pile foundations, of taking into account not only inertial bending moments, but also kinematic bending moments, in order to avoid significant structural damage. In this paper a 3D soil-pile FEM system is analysed. The system is subjected to a seismic input motion, applied at the base of the system, which represents the conventional bedrock. The FEM analyses lead to the evaluation of the kinematic bending moment distribution along the pile. Finally, the numerical results are compared with those coming from some simplified approaches available in geotechnical literature.

The paper describes a closed form pseudo-static solution for the estimation of the active earth-pressure coefficient for an earth-reinforced wall assuming a non-uniform profile of the seismic coefficients along the wall height and a distanced uniformly-distributed surcharge on the backfill surface. The static and seismic hydraulic conditions of the backfill are also accounted for. A parametric analysis is carried out and the obtained results are discussed.