This paper deals with the nonaxisymmetric dynamic behavior of fluid-filled buried orthotropic cylindrical shells/pipes subjected to a load moving along the axis of the shell. A thick shell model including the effects of shear deformation and rotary inertia is considered. A perfect bond between the shell and surrounding soil is assumed. The linear acoustic equation is used for the 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 for different soil conditions around the pipe. Results of empty and fluid-filled shells are compared. The presence of fluid inside the shell has small effect on the shell response. However, the deformations in the fluid-filled shell are normally more than those in the empty shell. The difference in the displacements of empty and fluid-filled shells is very small in flexural mode as compared to axisymmetric mode. The effect of fluid presence on the shell response is also influenced by the nature of the surrounding soil. NOMENCLATURE . c -apparent wave speed along the axis of the shell. cl = speed of dilational wave in the medium. C2 = speed of shear wave in the medium. cf -speed of dilational wave in the fluid. d r , d x , d B = components of displacement vector. E, I Ez, Eo = Young's moduli of the shell. <9! Gx= , G~B -shear moduli of the shell. h = thickness of the shell. h = nondimensional thickness of the shell. , kx , ko -shear correction factors. , n = mode shape number in tangential direction. P or (Ð) = intensity of the applied radial line load. , at NATIONAL UNIV SINGAPORE on June 28, 2015 jvc.sagepub.com Downloaded from 824 R = mean radius of the shell. U = nondimensional displacement of the shell middle surface in axial direction. u = displacement of the shell middle surface in axial direction. U, = displacement amplitude of the shell middle surface in axial direction. V = nondimensional displacement of the shell middle surface in tangential direction. v = displacement of the shell middle surface in the tangential ' , direction. Va = displacement amplitude of the shell middle surface in the tangential direction. W = nondimensional displacement of the shell middle surface in radial direction. w = displacement of the shell middle surface in the radial direction. wo = displacement amplitude of the shell middle surface in the radial direction. X = nondimensional moving axial coordinate. , a = scalar displacement potential in the medium. fl = nondimensional wave number of incident wave. ' r¡ 1, r¡2, ~13, q 4 -nondimensional orthotropy parameters of the shell. A = wavelength of the incident wave.