Flexural Response of a Plate on Viscoelastic Foundation

A mechanical model has been proposed to study the flexural response of a square plate resting on the viscoelastic foundation. A Burgers model is the series combination of Maxwell and Kelvin model, representing viscoelastic behaviour of soil very efficiently, and therefore, the same has been employed to idealize the foundation soil. The foundation has been modelled as a plate, and its time-dependent behaviour has been studied. Classical Kirchhoff’s theory of thin plates has been employed to undertake the flexural analysis of the plate. Governing differential equations have been derived and solved using the finite difference method with the help of appropriate boundary conditions. The results of a particular case of present work have been compared with those available in the literature in order to validate the proposed model. After validation, first the retardation time of the viscoelastic model, representing degree of rigidity of viscoelastic material, has been determined. Detailed parametric study has then been carried out to study the influence of various input parameters like magnitude of applied load, relative magnitude of elastic and viscous coefficients of Burgers model, tension in elastic membrane and the degree of consolidation, on response of plate in terms of its deflection and the bending moment. This work finds direct application in the analysis of raft foundations and rigid pavements.