A thesis study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1986

The quasi-static behaviour of a saturated porous elastic half space loaded on the surface by a disk load is investigated using a finite element analysis scheme. The two types of loading considered are vertical and horizontal loads. The porous elastic medium is governed by Biot's consolidation theory. For the numerical analysis, a functional based on a variational principle deduced from Gurtin's principle for this class of problems is used. Fourier Expansion with respect to the angular coordinate is utilized to reduce the 3-D problem to a 2-D problem, since only systems with axial symmetry subjected to asymmetric loading are considered. The far field behaviour of displacements and pore pressure of the medium is investigated; based on this investigation, an appropriate porous elastic infinite element is introduced to model the far field of the domain, utilizing the concept of singular contraction to a parental finite element (an algorithm named FESC). Laplace transforms are used to remove the time dependence of the set of equations resulting from the first variation of the functional; Shapery' s inversion formula is used to obtain the inverse Laplace transforms, resulting in a system which avoids step-by-step computations for this transient problem. The good agreement of numerical results with already known analytical solutions validates the present scheme for use in the solution of more complicated consolidation problems.