The effects of slope grade on the soil-pipeline interaction loading

Northern Crescent Inc. 是一家位于艾伯塔省卡尔加里的管道完整性评估公司，为管道提供地质灾害评估服务。这些评估包括分析地质灾害易发地区的管土相互作用，以及为石油和天然气管道行业提供适用性（FFS）评估。北新月遇到各种类型的地面运动。管道在这些地面运动中的性能尚不清楚。此外，现有设计规范/手册中的指南并未考虑坡度对管道地质灾害评估的影响。通过拟议的研究项目，Northern Crescent 将利用 Maghoul 博士及其团队的专业知识来推进对遭受地质灾害的管道进行 FFS 评估的技术。在目前的行业实践中，FFS对管道对抗地面运动的评估是通过数值模拟进行的，其中使用三个正交弹簧来代表周围的土壤。由于在实验室中对山体滑坡进行物理模拟是不可行的，研究人员通常将管道埋在土箱中，并沿首选方向拖动管道以测量管道上施加的土壤载荷。力-位移曲线用于定义管道行为数值分析所需的弹簧刚度。土弹簧的力-位移曲线最初是在假设地面平坦的情况下开发的。然而，当管道埋在斜坡上时，假设地面平坦可能会导致不保守的结果。因此，需要一种能够考虑地面坡度影响的先进数值技术。在这个拟议的合作研究项目中，将开发物理和数值建模技术来计算地面坡度对管道地质灾害评估的影响，这将有助于准确设计滑坡地区的管道。

Northern Crescent Inc. is a pipeline integrity assessment company based in Calgary, Alberta, that provides geohazard assessment services for pipelines. These assessments include analysis of pipe-soil interaction in the geohazard prone areas, and provision of Fitness For Service (FFS) assessments to the oil and gas pipeline industry. Northern Crescent encounters ground movement of various types. The performance of pipes with these ground movement is not well understood. Furthermore, the effect of the slope grade on this geohazard assessment against pipelines has not been considered in the guidelines available in existing design codes/manuals. Through the proposed research project, Northern Crescent will utilize the expertise of Dr. Maghoul and her team to advance the technology for FFS assessment of pipelines subjected to geohazards. In the current industry practice, the FFS assessment of pipelines against ground movement is conducted through numerical modeling, where three orthogonal springs are used to represent the surrounding soil. As it is not feasible to physically model a landslide in a lab, researchers usually bury a pipe in a soil box and drag the pipe in the preferred direction to measure the exerted soil loads on the pipe. The force-displacement curves are used to define the spring stiffness required for the numerical analysis of the pipeline behavior. The force-displacement curves for the soil springs were originally developed assuming that the ground surface is flat. However, when the pipe is buried in a slope, the assumption of flat ground surface might lead to non-conservative results. Therefore, an advanced numerical technique that can take the effect of ground slope into account is required. In this proposed collaborative research project, both physical and numerical modeling techniques will be developed to calculate the effect of the ground slope on the geohazard assessment of pipes, which will lead to an accurate design of pipelines in the landslide areas.