Bearing Capacity of Circular Footing Resting on Fiber-Reinforced Pond Ash Overlying Soft Clay

Abstract

Model footing tests were conducted of a circular footing resting on a randomly distributed fiber-reinforced pond ash (RDFP) layer overlying soft clay. The effect of varying the thickness of the pond ash layer over soft clay was studied. The reinforcement effect also was investigated by adding polypropylene fibers of different lengths with varying content percentages into the pond ash layer overlying soft clay. The results indicated that there is significant improvement in the ultimate bearing capacity with an increase in fiber length, fiber percentage, and RDFP layer thickness. The results also indicated that there is significant improvement of 80% in ultimate bearing pressure when soft clay at the top is replaced by a compacted pond ash layer of 1.5D thickness. The ultimate bearing pressure increased 54% with an increase in fiber length from 6 to 18 mm for a 1.5D thickness of the RDFP layer at 1% fiber content. The results of the model footing tests were validated with finite-element software PLAXIS 3D. The scale effect also was studied with the help of software by considering footings with diameters of 1, 2, 3, and 4 m.