Evaluation on Bearing Capacity of Ring Foundations on two-Layered Soil

This paper utilizes a finite element analysis to study the bearing capacity of ring footings on a two-layered soil. The upper layer, that the footing is placed on it, is soft clay and the underneath layer is a cohesionless sand. For modeling soils, Mohr–Coulomb plastic yield criterion is employed. The effects of two factors, the clay layer thickness and the ratio of internal radius of the ring footing to external radius of the ring, have been analyzed. It is found that the bearing capacity decreases as the value of ri / ro increases. Although, as the clay layer thickness increases the bearing capacity was alleviated gradually.

Authors:

• R. Ziaie Moayed
• V. Rashidian
• E. Izadi

Keywords:

• Bearing capacity
• Ring footing
• Two-layered soil

References:

[1] Terzaghi K. Theoretical soil mechanics. New York: John Wiley
andSons; 1943.
[2] Meyerhof GG. The ultimate bearing capacity of
footings.Geotechnique1951;2(4):301-32.
[3] Griffiths DV. Computation of collapse loads in geomechanics by finite
elements. IngArchiv 1989;59:237-44.
[4] Sloan SW, Randolph MF. Numerical prediction of collapse loads using
finite elements method. Int J Numer Anal Methods Geomech1982;6:47-
76.
[5] Burd HJ, Yu H, Houlsby GT. Finite element implementation of friction
plasticity models with dilation. In: Jinhong F, Murakami S, editors.
Proceedings of the international conference on constitutive laws for
engineering materials, vol. 2.Academic Publishers; 1989. p. 783-8.
[6] Manoharan N, Dasgupta SP. Bearing capacity of surface footings by
finite elements. ComputStruct 1995;54(4):563-86.
[7] Frydman S, Burd HJ. Numerical studies of bearing capacity factor Nc. J
GeotechGeoenvironEng ASCE 1997;123(1):20-9.
[8] Erickson HL, Drescher A. Bearing capacity of circular footings. J
GeotechGeoenvironEng ASCE 2002;128(1):38-43.
[9] Berezantzev VG. Limit equilibrium of a medium with internal friction
and cohesion in axisymmetric stress. Prikl Mat Mekh 1948;12:95-100
[in Russian].
[10] Saha MC. Ultimate bearing capacity of ring footings on
sand.M.Eng.Thesis, University of Roorkee, Roorkee, UP, India; 1978.
[11] Saran S, Bhandari NM, Al-Smadi MMA. Analysis of
eccentricallyobliquelyloaded ring footings on sand. Indian Geotech J
2003;33(4):422-46.
[12] Boushehrian JH, Hataf N. Experimental and numerical investigation of
the bearing capacity of model circular and ring footings on reinforced
sand. GeotextGeomembranes 2003;21:241-56.
[13] Kumar J, Ghosh P. Bearing capacity factor Ncfor ring footings using the
method of characteristics. Can Geotech J 2005;40(3):1474-84.
[14] Erickson HL, Drescher A. Bearing capacity of circular footings.
JGeotechGeoenvironEng ASCE 2002;128(1):38-43.
[15] Hansen BJ. A general formula for bearing capacity. Bull Dan
GeotechInst 1961;11:38-46.
[16] Meyerhof GG. Some recent research on the bearing capacity of footings.
Can Geotech J 1963;1:16-26.
[17] de Beer EE. Experimental determination of the shapes factors and the
bearing capacity factors of sand.Geotechnique 1970;20:387-411
[18] Caquot A, Kerisel L. Traite' de Me'canique des sols. Paris: Gauthier-
Villars; 1949 [in French].