Geomechanics and Engineering

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Bearing capacity of strip footings on unsaturated soils under combined loading using LEM

  • Afsharpour, Siavash (Department of Civil Engineering, Faculty of Engineering, University of Guilan) ;
  • Payan, Meghdad (Department of Civil Engineering, Faculty of Engineering, University of Guilan) ;
  • Chenari, Reza Jamshidi (Department of Civil Engineering, Faculty of Engineering, University of Guilan) ;
  • Ahmadi, Hadi (Department of Civil Engineering, Faculty of Engineering, University of Guilan) ;
  • Fathipour, Hessam (Department of Civil Engineering, Faculty of Engineering, University of Guilan)
  • Received : 2021.08.30
  • Accepted : 2022.10.20
  • Published : 2022.10.25
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Abstract

Bearing capacity of shallow foundations is often determined for either dry or saturated soils. In some occasions, foundations may be subjected to external loading which is inclined and/or eccentric. In this study, the ultimate bearing capacity of shallow foundations resting on partially saturated coarse-grained cohesionless and fine-grained cohesive soils subjected to a wide range of combined vertical (V) - horizontal (H) - moment (M) loadings is rigorously evaluated using the well-established limit equilibrium method. The unified effective stress approach as well as the suction stress concept is effectively adopted so as to simulate the behaviour of the underlying unsaturated soil medium. In order to obtain the bearing capacity, four equilibrium equations are solved by adopting Coulomb failure mechanism and Bishop effective stress concept and also considering a linear variation of the induced matric suction beneath the foundation. The general failure loci of the shallow foundations resting on unsaturated soils at different hydraulic conditions are presented in V - H - M spaces. The results indicate that the matric suction has a marked influence on the bearing capacity of shallow foundations. In addition, the effect of induced suction on the ultimate bearing capacity of obliquely-loaded foundations is more pronounced than that of the eccentrically-loaded footings.

Keywords

References

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