Initial imperfections and pipeline buckling

对能源的高需求要求将气态和液态能源资源从北方地区安全运输到需求地区。最近，冶金技术的进步使得制造高强度的钢管来密封和运输这些材料成为可能。虽然这些高强度管道可以通过减少所需的壁厚来降低初始成本，但它们也容易受到地面运动的影响，从而导致大的变形。这种地面运动主要是由于地面斜坡的运动和冻融区的相对沉降。在严重的地面移动情况下，这些大的变形可能导致容器的损失，对工业和环境产生非常大的影响。阿尔伯塔大学与管道行业合作，广泛研究了管道以褶皱和弯曲形式产生的大变形，并确定了管道中弯曲的主要因素是管道轮廓中初始缺陷的数量和分布（例如，偏离或圆度，偏离直线，波纹）。虽然数值模型能够基于一定的初始缺陷分布来预测管道的行为，但没有关于管道剖面和相关初始缺陷的数据。目前的项目建议测量制造管道中初始缺陷的数量，并比较行业中经常使用的不同管道制造商。拟议的项目依赖于制造特殊设备和购买高分辨率相机系统，这些系统能够以非常高的精度快速分析管道。结果将有助于对初始缺陷的类型、程度和分布进行分类，并允许对遭受大变形的能源管道进行精确建模。

The high demand of energy requires the safe transport of gaseous and liquid energy resources from northern regions to areas of demand. Recently, the advance in metallurgy has allowed the manufacturing of high strength steel pipelines for the containment and transport of such material. While these high strength pipelines allow for the reduction of the initial cost by reducing the wall thickness required, they are also susceptible to ground movements that can cause large deformations. Such ground movements are primarily due to movement of ground slopes and relative settlement of areas of freezing and thawing. In severe ground movement cases, these large deformations can lead to loss of containment with very high impact on the industry and the environment. The University of Alberta in collaboration with the pipeline industry has been extensively studying the large deformations of pipelines in the forms of wrinkles and buckles and has identified that a major factor for the initiation of buckles in a pipeline is the amount and distribution of the initial imperfections in the pipeline profile (e.g. out or roundness, out of straightness, ripples). While numerical models are able to predict the behaviour of the pipeline based on a certain distribution of initial imperfections, no data is available on the pipeline profile and the associated initial imperfections. The current project proposes measuring the amount of initial imperfections within manufactured pipelines and comparing the different pipeline manufacturers that are frequently employed in the industry. The proposed project relies on manufacturing special devices and the purchase of high resolution camera systems that are able to quickly profile the pipeline with very high accuracy. The results will help categorize the type, extent and distribution of the initial imperfections and will allow for accurate modelling of energy pipelines subjected to large deformations.