State detection and safety evaluation of submarine suspended pipeline

Due to the change of sea conditions, suspended sections will appear to a submarine pipeline, and its safety has attracted great attention. Herein, by adopting the side scan sonar detection technology and the sub-bottom profiling technology, a submarine pipeline was detected, with the buried, bare and suspended states of the whole pipeline learned. Meanwhile, the in-filled detection was performed for the suspended sections, with the seabed condition verified. In addition, a stress analysis model and a vortex-induced vibration analysis model were established for the submarine suspended pipeline, and based on the actual detection results, the suspension stress analysis and the vortex-induced vibration analysis of the submarine pipeline were carried out. The results show that the detection technology can accurately get the state change of pipeline. Definitely, one of the suspended sections of the whole pipeline is in dangerous state and the rest is in safe state. Conclusively, the research results could provide technical support to the safe operation of the submarine pipeline.