A Method of Strip Footings Design for Light Structures on Expansive Clays

Shallow stiffened footing, in particular the Vierendeel typology, are considered as a design techniques for structures on expansive soils which have proven their success as challenging solutions; combining economy and safety. The current study is investigating an analytical model for preliminary design of strip footings for light structures on expansive soils, in particular the Vierendeel beam. The developed model is used to calculate, through soil–structure interaction analysis, the algebraic expressions for the bending moment and the footing displacement at any point on the footing. The method is based on a simplification of the clayey ground reaction (Pi) and structure geometry and is derived from an integration of the beam-on-Winkler mound equation. The analytical model is then used to assess the effect of the structure loads on the contact state between the structure and the clayey ground (full or partial contact) as well as the impact of this contact state on the value of the maximum bending moment inside the beam. The results underlines the influence of the construction load on the contact state between the foundation and the swelling soil. The results shows that the bending moment in the footing strongly depends on the contact state between this footing and the clayey ground.