Hydrodynamic Force Model on Free Spanning Pipeline Subjected to Seismic Excitations

Firstly, a series of model tests of free spanning submarine pipeline are carried out on an underwater shaking table in the State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology. Hydrodynamic forces imposed on the span of submarine pipeline due to different direction excitations are studied. Secondly, finite element method on the base of the theory of interaction between fluid and structure is utilized to analyze the dynamic response of free spanning submarine pipelines subjected to earthquakes. Thirdly, based on Morison equation an improved hydrodynamic force model considering the effects of seismic exciting directions is proposed. Discretized equations of motion derived from the improved Morison equation is employed to analyze the dynamic response of free spanning submarine pipelines subjected to earthquakes. FE model is established to simulate the above experimental conditions. Finally, the comparison of numerical results with experimental results shows that the improved hydrodynamic force model could satisfactorily predict dynamic response on the free spanning submarine pipelines subjected to earthquakes.Copyright © 2008 by ASME