Experimental study on response of submarine pipeline over flat beds in steady flow

摘要

Model tests have been conducted on exible submarine pipelines over at beds subjectedto steady ow in the wave-current ume with 55m in length, 4m in width and 2.5m in depth. Thepipelines are made by exible pipe with 60mm in diameter and placed at various distances from aat bed. Gap to diameter ratio varied from 0.4 to 1.2 when the pipelines are not sagging. The owvelocity in the model tests ranged from 0.35 m/s to 0.6 m/s and water depth is 0.4m. The Reynoldsnumbers ranged from 2.1×10to 3.6×10within the subcritical Reynolds numbers range. Bendingstrain was measured by strain gauges bonded on the inner surface of the pipeline. The feature ofdynamic response is analyzed and discussed in time domain and frequency domain against variousgaps between the pipeline and the at bed.