Load transfer from axially loaded bar in a multilayered poroelastic medium

Abstract

The analysis of load transfer from an axiallyloaded elastic bar embedded in a multilayeredporoelastic medium is presented. The bar is consideredas a one-dimensional elastic continuum. The contactsurface between the bar and the multilayered medium isassumed to be perfectly bonded and fully permeable.Each layer of the multilayered medium is considered asa homogeneous poroelastic material and behavesaccording to Biot's theory. The vertical displacement of the bar is assumed byusing an exponential function with a set of arbitrarycoefficients. A variational formulation and an exactstiffness method are used to formulate the totalpotential energy functional of the bar-multilayeredmedium system. Minimization of the total potentialenergy functional is applied in order to determine thearbitrary coefficients. Finally, back-substitution ofthese coefficients into the assumed displacementfunction yields the time-histories of the axialresponses of the bar. A computer program was developed in order toevaluate the numerical solutions. The numericalresults obtained are in good agreement with those ofother investigators. The influence of layer propertieson the time dependent behavior of the bar are alsoinvestigated and discussed. It can be seen from theconclusions that the rate of bar displacement isdepended on the the permeability of each layer and theinitial and final displacement is controlled by theundrained and drained Poisson's ratio, respectively. Inaddition the moduli of elasticity of the bar andmultilayered medium and the bar length have significantinfluence on the magnitude of the vertical displacementof the bar.