This paper is concerned with the nonaxisymmetric dynamic response of a
n imperfectly bonded fluid-filled buried orthotropic cylindrical shell
excited by a plane longitudinal wave. A thick shell model, including
the effect of shear deformation and rotary inertia, has been taken. Fo
r the wave propagation in the fluid inside tire pipe, linear acoustic
equation has been used. The effects of fluid presence on the shell dis
placements have been studied for different soil conditions and at vari
ous angles of incidence of the longitudinal wave. The effects of bond
imperfection on the shell response have been compared with the effects
realized due to the presence of fluid inside the pipeline. Effects of
changes in the fluid density are also discussed. It is found that mag
nitude of the response of fluid-filled pipeline can become even more t
han that of an empty pipeline (without fluid), and, hence, it cannot b
e assumed that a fluid-filled pipeline will always furnish safe and co
nservative response.