Effect of different shape of footing on its load-settlement behaviour (circular, square and rectangular)

Abstract

An experimental investigation is carried out to study the effect of shape of footing on its bearing pressure, when rested on granular soil under centric loading condition. The model footing used in this study are circular, square and rectangle. Rectangular footing used here is a special case of the square footing having L/B ratio of 1.5 and 2 times the width of the square footing. Plate load test is carried out on the dry river sand with two different relative densities (60% and 80%) to obtain the relation between load-settlement and L/B ratio. From this relationship, the bearing pressure of the footing is determined; it has been observed that the bearing pressure varies in increasing order as Solid Circular, Square, and Rectangle. It is found that the bearing pressure varies as the L/B ratio increases in the case of the square footing. The square footing had higher bearing pressure than the circular footing, this may be due to the more confining effect in the case of square footing because for the same lateral dimension, area of square(width=15cm) is higher than the circle(diameter = 15cm). The experimental results are compared with the established bearing pressure theories and it found that the values are comparable and identical. The results revealed that the shape of the footing has a significant effect on its bearing pressure and the settlement characteristics.