Dynamics of a Pipeline Span on an Elastic Seabed

Natural frequencies, mode shapes and modal damping ratios must be estimated to assess subsea pipeline spans for vortex-induced vibrations (VIV) response direct wave loading. Several approximate solutions exist a linearly elastic pipe under constant axial force supported by springs beyond the span's shoulders. An exact analytical solution has only recently been published. That is used here in Rayleigh-Ritz approximation account arch action arising from combined effects of sag gravity loads restraint at The method allows survey data directly quantify action. Its accuracy confirmed finite element analysis. Further, ratio based on fractions potential energy bending, force, soil springs, all which are determined analytically. Thus, it found that effective increases without bound as load approaches buckling compression.