Effect of metal strip reinforcement on bearing capacity of strip footing on sand

Abstract

This study has been carried out to investigate the effect of metal strip reinforcement on bearing capacity of strip footing resting upon sand deposit. The sand bed consists or horizontally placed metal strip reinforcement in one layer, two layers and three layers. Model tests were conducted to investigate the bearing capacity and settlement or strip footing in two different speed of loadings. The experimental set-up has been modified and re-modeled. All of the measuring devices were connected to a computer through the data-Logger. The out of plane deformation or the loading frame was eliminated by using vertical-ball-bearing system at the mid-level guide-beam. Tests were carried out in a tank on beds or sand having average densities varying from 14.67 kN/m3 to 15.78 kN/mJ . The sand bed thickness was maintained to 3.<) times the least dimension of the footing. Strain controlled vertical loads were applied on the footing placed on the surface or sand bed. The effect of number of reinforced layer, effect of speed on bearing capacity arc studied. The results arc established, discussed and compared among different layers or reinforcement and two rates of speeds. From the experimental result for the case or reinforced sand bed, it is observed that the bearing capacity of the footing increases significantly compared to an unreinforced bed. In most or the tests, it is observed that with the increase in number of the layers of reinforcement, bearing capacity has been improved. Due to change in speed of loading the bearing capacity and settlement have been affected. The results also indicate that for slow speed, bearing capacity was or higher value than that of higher speed of loading. On the other hand, settlement due to slow speed or loading is lower than that or higher speed of loading. In most of the cases, the bearing capacity II1creases with the increase or metal strip reinforcell1enl. In some cases the results show, opposite trend. For unreinforced bed, failure outcrop arises on the sides which distance of 2B to 3B from the edges of footing. III the case of reinforced bed or sand, failure pattern was not very e1ear at 20%, settlements.