A refined analytical model for landslide or debris flow impact on pipelines. Part I: Surface pipelines

As one of the most destructive geohazards, submarine landslides pose significant risks to pipelines and seabed installations. Deepwater pipelines are often laid on the seabed without pre-trenching or cover, and especially light pipelines are often laid on the surface of the seabed, which makes them directly exposed to debris flows. Determining a pipeline behavior subjected to a landslide is a great challenge and still is a matter of further research. In this work, an analytical model is established to analyze the behavior of light pipeline subjected to a landslide. In this model, the pipeline is divided into four segments according to the different loading conditions along the pipeline. The governing equations of different segments are established on the basis of beam theory. Then, by virtue of the continuity conditions and boundary conditions, the explicit expressions of different segments are obtained. The influences of the drag force, slide width, the lateral and axial soil resistance are investigated through parametric studies, and some important and valuable conclusions are obtained.