Dynamic response of framed underground structures

The dynamic response of framed underground structures under conditions of plane strain is numerically determined in this work. The soil deposit surrounding such structures is assumed to be horizontally layered and resting on a rigid base from which shear waves originate, and to exhibit linear elastic or viscoelastic material behavior. The methodology consists of applying the Laplace transform with respect to time to the governing equations of motion of the soil and the structure and subsequently constructing dynamic stiffness influence coefficients for typical soil and structure elements. A numerical inversion of the solution obtained by the finite element methodology employing these influence coefficients in the transformed domain yields the response as a function of time. Numerical examples to illustrate the method and demonstrate its advantages are presented.