A comprehensive analysis of multiple factors affecting the impact pressure generated by landslide wave on underwater pipelines in shallow sea areas

Landslides and secondary wave disasters have become critical factors in subsea pipeline integrity breaches. Pipeline failures and subsequent hydrocarbon releases may escalate into explosion events, posing substantial risks of marine environmental contamination and potential geohazards. Therefore, rigorous analysis of landslide-induced pipeline failure mechanisms holds significant academic and practical value. The paper established a physical experimental model to analyze the influence of four factors, such as speed and water entry angle, on the impact pressure of underwater pipelines and the change of wave shape. In this paper, the orthogonal test method is used to study the primary and secondary relations of the influence of various factors on the 27 times impact pressure of underwater pipeline. The findings of the single factor test indicate that the maximum swell height and impact pressure increase with slide speed; conversely, the maximum swell height and impact pressure decrease with increasing landslide angle. The slider volume increases with the maximum wave height and impact pressure. The maximum wave height produced by impacting decreases and the impact dynamic pressure increases as the water depth increases because as the slide block slides into the water, the water may be transferred to the lower part of the slide block. Ultimately, the primary and secondary relationships of each element on the pipeline impact pressure are landslide volume > water depth > landslide entry velocity > landslide angle, as determined by analyzing the range of orthogonal test findings. Therefore, for critical infrastructure projects entailing subsea pipeline installation, a rigorous assessment of unstable slope volume, operational water depth, and seabed inclination is imperative to minimize the likelihood of catastrophic failures.