Experimental Investigation of Eccentric Loading Effect on Circular Footing Located on Sandy Bed with a Weak Thin Layer

Document Type : Research Article

Authors

1 Department of Civil Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran

2 Faculty of Civil Engineering, Architecture and Art, Science and Research Branch, Islamic Azad University

3 Assistant Professor, Department of Civil Engineering, Shahr-e-Qods Branch Islamic Azad University, Tehran, Iran

Abstract

In some cases, there is a weak thin interlayer in the soil profile, which may not reveal these complications in geotechnical studies. Also, most of shallow footings are subjected to eccentric loadings that due to the existence of such loads, moments are imposed on the footing and as a result, the footing rotates and the pressure under the footing does not remain uniform. In this research, an experimental investigation has been carried out on a circular footing model located on a homogeneous sand bed with a weak thin layer with different thicknesses and depths of placement under vertical eccentric loads by a small-scale physical model of the soil-footing system. Physical model tests are performed in a cylindrical steel tank with an inner diameter of 70 cm and a height of 70 cm. Investigations have been carried out by changing the thickness and depth of placement of a weak thin layer due to eccentric loadings. The results show that the existence of a weak layer and eccentric load has increased the rotation of circular footing compared to the homogeneous sand bed. So in the sand bed with a weak thin layer, the maximum rotation of circular footing has been obtained equal to 8.2 degrees for eccentric load 0.0625D (D is the diameter of footing) and thickness of weak thin layer 0.2D and depth of placement 0.5D and the minimum rotation of circular footing for homogeneous sand with eccentric load of 0.0625D is equal to 4.5 degrees, which shows a reduction of 45%.

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References

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Amirkabir Journal of Civil Engineering
Volume 57, Issue 1
April 2025
Pages 3-24

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