Dynamic Response of Fluid‐Filled Buried Orthotropic Cylindrical Shells

Abstract

This paper deals with the nonaxisymmetric dynamic behavior of fluid‐filled buried orthotropic cylindrical shells/pipes excited by plane longitudinal waves. A thick shell model including the effects of shear deformation and rotary inertia is taken. A perfect bond between the shell and the surrounding soil is assumed. The linear acoustic equation is used for wave propagation in the fluid inside the pipe. Results are presented for the axisymmetric as well as the flexural mode for different orthotropy parameters of the shell and also for different soil conditions around the pipe/shell. Results of the empty and fluid‐filled shells are compared. Effects of changes in the fluid density are also discussed. The presence of fluid inside the shell significantly alters the shell response. The effect of fluid, in general, is comparable to the effects of variation in the orthotropy parameters of the shell and also to the effects due to changes in the soil condition. In the flexural mode, deformations in the fluid‐filled shell are normally more than those in the empty shell. Finally, it is concluded that it may not always be safe to assume that the consideration of fluid presence will give only a lower and conservative dynamic/seismic response compared to the empty shell.