ABSTRACT
A series of model footings tests were conducted on unsaturated sand with cavity. The cavity was created using an easily found commercial balloon, placed, and expanded within the model soil. The unsaturated soil was vertically loaded using a circular model footing of diameter B = 30 mm after the balloon was deflated. The load versus displacement curves reveal the increase of the ultimate bearing capacity of footing on sand with cavities in deeper layers. The Rigid Plastic Finite Element analysis results are introduced to apprehend the variation of bearing capacity of a footing resting on ground with cavity and confirm the experimental results. As a result, the trade-off relationship between matric suction and effective stress, from the fact that giving higher values of ultimate bearing capacity in deeper cavity cases and lower ultimate bearing capacity in shallower cavity cases, comparing to the cases without consideration of the ground water table.
