Wave‐Induced Breakout of Half‐Buried Marine Pipes

Abstract

An experimental study is conducted in order to identify the major physical processes leading to the breakout of half‐buried submarine pipelines from the seafloor under ocean‐wave action. Both the hydrodynamic loading on the exposed surface of the pipe as well as the pore‐pressure distribution on the buried surface were measured. The resulting displacement histories of the pipe were recorded and analyzed in order to identify the critical pipe‐soil‐wave conditions for the detachment of the pipe from the seabed. The paper examines the balance of the pipe under the combined lift and drag loading from the water wave. The experimental coefficients of drag, lift, and added mass have been calculated by the least squares method and compared with theoretical predictions. As for the soil response, a simple theoretical model is worked out to describe the pore‐pressure resistance force at the soil‐pipe interface. An experimental breakout force‐time power law is obtained and compared with the theoretical model.