Abstract: This paper presents a semi-numerical and semi-analytical solution to the problem of an Euler-Bernoulli beam on multilayered isotropic elastic soils by the coupling of the finite element method and the boundary element method on the basis of the cooperation of the vertical displacements and the frictionless contact at the soil-beam interface, where the subgrade is assumed as a multilayered isotropic elastomer, the finite element method is applied to model the beam and the boundary integral method at the soil-beam interface. Then a corresponding program is compiled on the basis of the present theory. By comparing the solutions of this paper with the existing solution, the accuracy of the present theory is verified. The responses of elastic beams on both layered foundation model and the equivalent homogeneous one are further analyzed and compared. The results show that the characteristics of the beam on layered foundation model differ greatly from those of the beam on equivalent homogeneous foundation model; so layered foundation beam model should be adopted in practical engineering.

Key words: layered soils, Euler-Bernoulli beam, finite element method(FEM), boundary element method(BEM), coupling analysis