Settlement of Surface Footings - FLEA5

Authors:
John Small
John Booker


FLEA5 (Finite Layer Elastic Analysis) is a Windows based program that can calculate the stresses and displacements within a multi-layered soil deposit of finite thickness generated by multiple uniform surface loadings. The surface loading may be applied over a circular, strip or rectangular region. Therefore, this program could be used for standard settlement computations or in specialised areas of interest such as pavement design where the wheel loads are assumed to apply a rectangular or circular loading.

All data may be entered into the program by an in-built screen editor. This makes data preparation and checking extremely easy. Data from a run may be stored on disk and re-edited on a subsequent run. Plots of stresses, displacements or strains can be made along vertical sections or along horizontal sections within FLEA5. Contours of displacements, stresses, deformed grids and displacement vectors can be produced with the optional plotting program FLPLOT. An example of the screen editor which is used for data input is shown below.

FLEA5 uses an exact finite layer method of analysis which has been developed and published by the authors. This is computationally more efficient and dramatically reduces the size of the data set when compared with conventional finite element analyses. However, the advantages of a finite element analysis are retained; ie. a horizontally layered soil deposit of any complexity (present program limit is 100 layers) may be modelled by simply specifying for each layer its thickness and elastic soil properties. The layer may be anisotropic or isotropic, and in the latter case an incompressible soil (Poisson's ratio = 0.5) presents no difficulty.