Numerical and photoelastic analyses of reinforced soil under footing loads

The work presented in this thesis is concerned with the numerical andexperimental analyses of soil-reinfrcement model systems under threedimensional conditions. The case of a surface rigid isolated footingsubjected to a uniform vertical load and resting on a space homogeneouselastic foundation soil with and without horizontal reinforcement layers wasstudied. The three dimensional photoelasticity and finite element techniqueswere used as an experimental and theoretical methods of analysis,respectively.In the experimental work, the elastic foundation soil was representedby photoelastic material (gelatine) and aluminum foils were used asreinforcements. In the theoretical work, a computer program which utilizedthe finite element technique was developed to predict the displacements,strains and the stresses in the reinforced soil models. It comprised linearelastic representations of the stress-strain behaviour. All studied models inboth experimental and theoretical analyses were tested under the samefooting stress and only the depth, length, number, thickness and surfaceroughness of the reinforcement layers were varied to study the effect ofreinforcement on the system behaviour.The results of all reinforced models were compared with those of thewithout reinforcement model to study the effect of reinforcement. Theexperimental results of all studied models were compared with thecorrosponding theoretically predicted results in order to assess the validityof the theoretical results. The distributions of the normal and shear stressesat different depths below the footing for all studied models were obtained.Also the vertical displacements for the model elements as well as the footingsettlement were studied. The effect of the depth, length ratios and thenumber of reinforcement layers on the behaviour of model systems werestudied. The effect of the thickness and surface roughness of thereinforcements were also obtained. .