Strain Based Design for Buried Steel Pipelines

埋地钢质管道基于应变的设计

• 批准号: RGPIN-2017-06606
• 负责人: Cheng, JungJune
• 金额: $ 1.53万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712271
• 关键词: Strain; Based; Design; Buried; Steel

Pipelines are one of the most economical modes of transportation for oil and gas from the location of the resources to the market. They are a key factor influencing the Canadian energy industry and overall economy. Energy pipelines are designed to transport pressurized highly flammable substances over a long distance, therefore, safety of the pipelines is paramount throughout the life of the infrastructure. To minimize the environmental and temperature effects, most of pipelines in Canada are buried underground. During the operation, pipelines are normally sustained a combination of circumferential stresses due to the internal pressure and longitudinal stresses induced by external loads/deformations. These external loads/deformations are primarily the result of soil movement and temperature effects. The stress design method is normally used to design these complex combined loading conditions. However, due to the complex nature of each ultimate limit state of a buried pipeline under internal and external loads/deformations, the stress design method is unable to address the needs of pipeline design, maintenance and operation. The strain based design method is proposed here, in recognizing various ultimate limit states of a buried pipe under combined loading conditions. Both the critical buckling compressive strain and tensile fracture strain capability will be included. The post-buckling behaviour of a buried pipe, based on the past research, has shown significant reserve capacity and unique behaviour after buckling. The inclusion of post-buckling strength into the strain based design will yield a more economical, rational and safe design. The various parameters will be investigated in this program, including different grades of steel, diameter to thickness (D/t) ratios, internal pressures, external loads, girth welds, corrosion, defects (or dents), and cold-bend. The limit states of a buried pipe under various combined loading conditions will be identified and corresponding strain limits will be proposed. Due to the harsh environmental and unpredictable operational conditions of a buried pipeline, a probability based risk assessment is proposed for a safe operation of a pipeline. Structure health monitoring methodology will be used in conjunction with the strain based design methods in developing the assessment tool. The signature patterns of each limit state will be studied and developed using the finite element method. The feasibility of using fibre optic sensing (FOS) technology in measuring distributed strains of a buried pipe will be investigated. Finally, structural health monitoring programs using various innovative sensing technologies will be proposed for each limit state of a buried pipe and its unique responding signature patterns.

管道是从资源到市场所在地的石油和天然气运输方式之一。它们是影响加拿大能源行业和整体经济的关键因素。能源管道旨在将加压高度易燃的物质在长距离上运输，因此，管道的安全性在整个基础设施的整个寿命中至关重要。为了最大程度地减少环境和温度影响，加拿大的大部分管道都被埋葬在地下。在操作过程中，由于内部压力和外部载荷/变形引起的纵向应力，管道通常是圆周应力的组合。这些外部载荷/变形主要是土壤运动和温度影响的结果。 应力设计方法通常用于设计这些复杂的组合加载条件。但是，由于内部和外部负载/变形下埋入管道的每个最终极限状态的复杂性质，应力设计方法无法满足管道设计，维护和操作的需求。 此处提出了基于应变的设计方法，以识别合并加载条件下埋入管道的各种最终极限状态。临界屈曲压缩应变和拉伸断裂应变能力都将包括在内。基于过去的研究，埋入管道的弯曲后行为显示出屈曲后的储备能力和独特的行为。在基于菌株的设计中插入后的强度将产生更经济，理性和安全的设计。该程序将研究各种参数，包括不同等级的钢，直径至厚度（D/T）比，内部压力，外部载荷，腰围焊缝，腐蚀，缺陷（或凹痕）和冷弯曲。将确定在各种组合加载条件下埋入管道的极限状态，并提出相应的应变限制。 由于埋入管道的环境和不可预测的操作条件，提出了基于概率的风险评估，以确保管道的安全操作。结构健康监测方法将与开发评估工具的基于应变的设计方法结合使用。将使用有限元方法研究和开发每个极限状态的签名模式。将研究使用光纤传感（FOS）技术来测量埋入管道的分布菌株的可行性。最后，将针对埋入管道的每个极限状态及其独特的响应签名模式提出使用各种创新感应技术的结构健康监测计划。