Entropy Identification of Pipeline Failure under Flood

Crossing river pipeline could be eroded by flood crushing, so that part of the pipeline will be exposed and subject to a considerable flood force. In this paper, mechanical analysis models of exposed part and unexposed part of pipeline under flood are established in considering the inner pressure of pipeline and the pipeline-soil interaction. Mechanical state of pipeline is calculated in using global analytical searching method, and entropy based on strain energy of zones is obtained simultaneously. Besides the variation of strain energy entropy with flood velocity is achieved. The study shows that the variation of strain energy entropy versus flood force could better reflect the yield feature of whole pipeline. The curve of strain energy entropy can be easily divided into 3 stages corresponding to the non-yield stage, the partial yield stage and the failure stage respectively, which indicate the yield or failure state of pipeline clearly. The boundaries of stages are significantly influenced by diameter, thickness, exposed length of pipeline, and less affected by inner pressure and depth of pipeline relatively. In addition, the entropy identification could be used as a new method to identify the failure state of pipeline under flood.