In recent years, the interaction between submarine slide runout and offshore pipelines has received extensive attention, based on the need to protect pipelines crossing regions susceptible to submarine slides. The interaction force between the slide material and a pipeline may be resolved into horizontal and vertical components, but with most attention to date focusing on the former while the latter has not been studied thoroughly. This paper reports the results from a series of multiphase flow (slide material and the ambient seawater) numerical simulations using a computational fluid dynamics (CFD) approach aimed at investigating the vertical forces during submarine slide flow around a pipeline at different gap ratios (pipeline-seabed gap normalized by pipeline diameter) from 0.08 to 10.0 and at Reynolds numbers ranging from 0.38 to 267. The oscillatory characteristics and magnitude of the vertical forces for different gap ratios are discussed. The effects of the gap ratios on the geotechnical and inertial components of the slide-pipeline vertical forces are analyzed systematically using a hybrid geotechnical-fluid mechanics framework. From the results of the CFD simulations, a modified hybrid geotechnical-fluid mechanics method to estimate the slide-pipeline vertical forces is developed considering the effects of pipeline-seabed gaps.

近年来，基于保护穿越易受海底滑道影响的区域的管线的需求，海底滑道跳动与海上管道之间的相互作用受到了广泛关注。滑动材料和管道之间的相互作用力可以分解为水平和垂直分量，但迄今为止，最受关注的是前者，而后者尚未进行深入研究。本文报告了一系列使用计算流体力学（CFD）方法进行的多相流（滑动材料和周围海水）数值模拟的结果，旨在研究在不同间隙比下管道周围海底滑动流期间的垂直力（管道-由管道直径归一化的海底间隙）从0.08至10.0，雷诺数范围从0.38至267。讨论了不同间隙比下的振动特性和垂直力的大小。使用混合岩土-流体力学框架，系统地分析了间隙比对滑管垂直力的岩土和惯性分量的影响。从CFD模拟的结果出发，考虑到管道-海底间隙的影响，开发了一种改进的混合岩土-流体力学方法来估算滑管垂直力。