Dynamic Analysis of Foundations on Saturated Clay Using an Energy Absorbing Layer

Abstract

In this study, a method to model the semi-infinite extension (unboundeddomain) of the saturated soil is developed. In this method, the unbounded domain isreplaced by an absorbing layer of finite thickness with properties that appreciablyreduce the wave reflection into bounded domain. In this layer, the soil is representedby the same properties as in the soil close to the foundation (bounded domain) and amodel of frequency-dependent damping is implemented.A three-dimensional dynamic analysis of rectangular footing on a saturatedsoil is carried out. The foundation is subjected to four cycles of harmonicforce. The coupled dynamic equations with u-p formulation based on thedynamic consolidation theory are used to simulate the soil skeleton and porefluid responses. The solid particles of the soil are represented by linearelastic behavior. It was found that a decay in wave can be noticed when theunbounded domain of the saturated soil is represented by the energyabsorbing layer. In addition, the maximum displacement of the foundationwill be decreased due to using the energy absorbing layer in comparison withthe elementary boundaries. The excess pore water pressure that developedduring the dynamic loading will be dissipated with time in a fast rate due tousing the energy absorbing layer.