WAVE-SOIL-PIPE COUPLING EFFECT ON SUBMARINE PIPELINE ON-BOTTOM STABILITY

摘要

Wave-soil-pipe coupling effect on the untrenched pipeline stability on sands is for the first time investigated experimentally. Tests are conducted in the Ushaped water tunnel, which generates an oscillatory flow, simulating the water particle movements with periodically changing direction under the wave action. Characteristic times and phases during the instability process are revealed. Linear relationship between Froude number and non-dimensional pipe weight is obtained. Effects of initial embedment and loading history are observed. Test results between the wavesoil-pipe interaction and pipe-soil interaction under cyclic mechanical loading are compared. The mechanism is briefly discussed. For applying in the practical design,more extensive and systematic investigations are needed.