EFFECT OF FLUID PRESENCE ON THE NON-AXISYMMETRICAL DYNAMIC-RESPONSE OF IMPERFECTLY BONDED BURIED ORTHOTROPIC PIPELINES DUE TO INCIDENT SHEAR-WAVE

This paper deals with the non-axisymmetric dynamic response of an impe rfectly bonded buried fluid-filled orthotropic pipeline excited by she ar waves travelling in the surrounding infinite medium. A thick shell model has been taken which includes the effect of shear deformation an d rotary inertia. For the wave propagation in the fluid inside the pip e, the linear acoustic equation has been used. The effects of bond imp erfection on the shell response have been compared with the effects re alized due to the presence of fluid inside the pipeline. The results h ave been obtained at various angles of wave incidence and for differen t soil conditions. The effects of changes in the fluid density are als o discussed. Although the formulation has been presented for SV- and S H-wave excitations, numerical results are given for the case of incide nt SH-wave only. It is found that under certain conditions, the consid eration of fluid inside the pipeline may lead to even higher value of shell deformation than that observed due to the imperfect bond.