This paper presents a fully analytical solution, together with explicit exp
ressions, for the steady-state response of a homogeneous 3D space subjected
to a spatially sinusoidal, harmonic line load. In the literature, this pro
blem is often referred to as the two-and-a-half-dimensional fundamental sol
ution or two-and-a-half-dimensional Green's functions. These equations are
of great usefulness in the formulation of 3D elastodynamic problems by mean
s of integral transforms methods and/or boundary elements. The final expres
sions are validated here by applying the equations to the problem of a 3D p
oint load, for which the solution is known in analytical form.