Research Articles | Challenge Journal of Structural Mechanics

Modification of the effective area method on two-way loaded shallow foundations

Mustafa Aytekin


DOI: https://doi.org/10.20528/cjsmec.2019.04.004

Abstract


In rectangular/square based and two-way loaded (two-way eccentric) shallow foundations, four zones in which the resultant load might act are defined in the effective area method. Three out of the four zones that are employed in the determination of the effective areas overlap around kern. Only one zone that has a triangular-shaped effective area (called as case 1 in the literature) out of the four zones has no overlap with the others. The resultant load will always be out of the kern for case 1, and also it might be out of the kern for the remaining three cases. Design of foundations is not acceptable in general if the resultant load acts out of the kern. In the present study, the four cases are reconsidered. The zones on which the resultant load can be acting for the four cases are modified because these zones are overlapped partly. The modification has been made to have clear borders between the zones. On top of that, zone 4 is divided into two. A new zone corresponding to the area of kern is defined as zone 5. The design will be accepted if the resultant load acts within zone 5 (the kern). Also, the graphs in use to determine the dimensions of the effective areas are eliminated since it is not precise. Formulas are derived to determine the dimensions of the effective areas instead of using the graphs. Two new criteria are discovered and proposed to check whether the resultant load acts outside, inside or on the borderline of zone 5 (the kern).


Keywords


shallow foundations; two-way eccentricity; effective area method; bearing capacity

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References


Badakhshan E, Noorzad A (2017). A simplified method for prediction of ultimate bearing capacity of eccentrically loaded foundation on geogrid reinforced sand bed. International Journal of Geosynthetics and Ground Engineering, 3(2), 1-15.

Das MB (2007). Principles of Foundation Engineering. 6th edition, CENGAGE Learning, Hampshire, UK.

Highter WH, Anders JC (1985). Dimensioning footings subjected to eccentric loads journal of geotechnical engineering. Journal of Geotechnical Engineering, ASCE, 111(5), 659-665.

Krabbenhoft S, Damkilde L, Krabbenhoft H (2012). Lower-bound calculations of the bearing capacity of eccentrically loaded footings in cohesionless soil. Canadian Geotechnical Journal, 49(3), 298-310.

Loukidis D, Chakrabory T, Salgado R (2008). Bearing capacity of strip footings on purely frictional soil under eccentric and inclined loads. Canadian Geotechnical Journal, 45(6), 768-787.

Meyerhof GG (1953). The bearing capacity of foundations under eccentric and inclined loads. Proceedings, 3rd International Conference on Soil Mechanics and Foundation Engineering, Zurich, Vol. 1, 440-445.

Meyerhof GG (1963). Some recent research on the bearing capacity of foundations. Canadian Geotechnical Journal, 1(1), 16-26.

Prakash S, Saran S (1971). Bearing capacity of eccentrically loaded footings, Journal of the Soil Mechanics and Foundation Division, ASCE, 97(SM1), 95-117.

Sahu R, Patra CR, Sobhan K, Das BM (2019). Ultimate Bearing Capacity Prediction of Eccentrically Loaded Rectangular Foundation on Reinforced Sand by ANN. In: Meguid M, Guler E, Giroud J (eds) Advances in Geosynthetics Engineering. GeoMEast 2018. Sustainable Civil Infrastructures. Springer, Cham.

Terzaghi K (1943). Theoretical Soil Mechanics. Wiley, New York.

Vesic AS (1973). Analysis of ultimate loads of shallow foundations. Journal of the Soil Mechanics and Foundation Division, ASCE, 99(SM1), 45-73.


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