Dynamic analysis of foundation resting upon elastic half-space

In recent years a considerable effort in the general area of dynamichas been devoted to the subject that links the two fields of soil andstructural mechanics, namely, the interaction between the structure andthe underlying soil. The reason for this interest in foundation dynamicslies behind an increased activity in the construction of dynamicallysensitive structures, e.g. power plants, multistory buildings, industrialinstallations, offshore platforms etc., and the need for protection of theman-made environment from major disasters such as earthquakes andother physical or man-created disturbances.This thesis addresses the problem of externally applied loads, for thecase of a raft foundation resting on a linear elastic, homogeneous andisotropic half-space which represents the soil medium. Both massless andmassive foundations are considered. With the principle of superpositionavailable, the linearized foundation-soil system can be separated into twosimpler substructures. The finite element method has been used torepresent the plate bending foundation. whereas the elastic half-spacehas been formulated by the numerical continuum method. This method ofanalysis simplifies the mechanical behaviour of the soil-footing contactsurface by assuming a relaxed boundary. The contact interface of thefoundation and soil medium is discretized into rectangular subregions.Simple numerical integration is conducted to evaluate the complexfrequency dependent impedance coefficients. Solving each of thesesubstructures separately, the solutions are then combined through