ABSTRACT
The study was to evaluate the bearing capacity of the soil and to predict accurately the settlement of the foundation using plaxis 3D. The design of foundations is generally controlled by settlement rather than bearing capacity. As a consequence, settlement prediction is a major concern and is an essential criterion in the design process of foundations. Therefore, the study focused on the total settlement prediction.
Soil sample were obtained from the site at a depth of 0.6m and the engineering properties of the soil were carried out viz: Atterberg limits, triaxial test, specific gravity, compaction and grain size/sieve analysis. These properties were used to evaluate the bearing capacity and were also imputed in the plaxis 3D for the prediction of the total settlement.
The engineering properties of the soil obtained were: Cohesion=22.0KN/m2, Friction Angle=2.18°,Young's modulus=60.12KN/m2, Saturated unit weight of soil=18.44 KN/m3, dry unit weight of soil was=16.43KN/m3 and the bearing capacity of the soil was evaluated to be 200KN/m2. Imputing the properties into plaxis 3D, the predicted total displacement for the footing without external load was 0.00128m and 0.0124m with external load which is negligible for any structure. Therefore for any foundation type, plaxis 3D will be recommended since it is faster to analyse and data can easily be adjusted instead of a redesign for a predicted unsuitable foundation.
