Bearing Capacity and Settlement Characteristics of Sand Subgrades with Vertical Reinforcement Supporting a Square Footing

Abstract

The restraining effects in the sand subgrade under the footing can be provided by inserting the vertical reinforcing bars beyond the footing base without disturbing the subgrade below the footing. This technique of soil reinforcement can be quite beneficial for the footings where improvement is necessary. This paper presents the results of model square footing tests with vertical reinforcements inserted into the sand subgrade beyond the footing base only. The variables selected for the investigation were spacing of vertical reinforcement, extent of reinforcement from the edge of footing, length of reinforcement, diameter of reinforcement, width of footing and surface characteristics of the reinforcement. The values of theoretical bearing capacity of reinforced sand subgrade were determined using the method of slices and compared with experimental results. It was found that results were comparable particularly when the length of reinforcement and extent of reinforcement were two times the footing width.