Geotechnical and Geological Engineering

, Volume 37, Issue 5, pp 4099–4120 | Cite as

Eccentricity Effects on Bearing Capacity of Strip and Square Footings on Two-Layered Clay

  • Konstantina PapadopoulouEmail author
  • George Gazetas
Original Paper


The undrained ultimate capacity to combined (M, V) loading of strip and square foundations on a two-layered clay deposit is investigated. Extensive two and threedimensional parametric finite element analyses are carried out in terms of the ratio of the undrained shear strength of two layers, the normalized thickness of the top layer and the normalized load eccentricity. Two basic cases are separately investigated, referring to strength ratios higher or lower than unity. The assumption of effective width of the foundations, to account for eccentricity, generally adopted for homogeneous soil, is extended for two layers. The results are mainly presented in terms of modified bearing capacity factors for strip or square footings for a wide range of dimensionless problem parameters. However, for a better visual understanding of how the bending moment affects the ultimate vertical load failure loci diagrams (“yield surfaces”) in M, V space are also presented. Emphasis is given to developing insight into the particular failure mechanisms of most examined cases.


Clays Bearing capacity Eccentricity Square footings Failure mechanism Numerical analysis 

List of Symbols


Width of footing


Effective width (B − 2e)


Eccentricity of loading


Thickness of upper clay layer


Horizontal load


Bending moment


Normalized ultimate moment

\({\text{N}}_{\text{C}} ,{\text{ N}}^{\text{ * }}_{\text{C}}\)

Bearing capacity (B.C.) factor for centric loads on strip or square footings, respectively

\({\text{N}}_{\text{C1}} ,{\text{ N}}^{\text{ * }}_{\text{C1}}\)

Equivalent B.C. factor for centric loads on strip or square footings in case of two layered clays

\({\text{N}}_{\text{C1,e}} ,{\text{ N}}^{\text{ * }}_{\text{C1,e}}\)

Equivalent B.C. factor for eccentric loads on strip or square footings in case of two layered clays


Ultimate bearing capacity pressure


Shape factor


Strength ratio (su,2/su,1)


Undrained shear strength


Vertical load


Normalized ultimate vertical load


Ultimate centric vertical load


Ultimate eccentric vertical load


Unit weight of the clay


Inclination of load

\(\uplambda_{\text{N}} , \,\uplambda^{\text{ * }}_{\text{N}}\)

Ratio of bearing capacity factors for strip or square footings


Poisson’s ratio



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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.National Technical University of AthensAthensGreece

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