Investigation of pull-out behaviour of small diameter medium density polyethylene pipes

小直径中密度聚乙烯管材拔出性能研究

• 批准号: 514564-2017
• 负责人: Dhar, Ashutosh
• 金额: $ 4.3万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649202
• 关键词: Investigation; pull; out; behaviour; small

Pipelines play an important role in modern society through transporting liquids and gases from the source to the**users. According to Natural Resources Canada, about 825,000 kilometers of oil and gas transmission, gathering**and distribution pipelines traverse Canada. Many of these pipelines pass through the areas prone to landslides.**Soil movement due to landslides may cause longitudinal, transverse or combined loads on the pipelines,**depending upon the orientation of the pipeline with respect to the moving ground. The existing design**guidelines for structural integrity assessment of pipelines in landslide areas were developed based on the**observations for rigid pipes, which may not be applicable to flexible pipes, such as Medium Density**Polyethylene (MDPE) pipes. However, flexible polyethylene pipes including MDPE pipes have been widely**used over the last few decades due to their various advantages. The design method for the assessment of the**performance of MDPE pipelines subjected to landslide loading is not well-developed. Full-scale tests and finite**element (FE) modelling of MDPE are also very limited. In the proposed research, a set of full-scale tests of**small diameter MDPE pipe will be conducted using the facility at Memorial University of Newfoundland**(MUN) to develop a database and an improved understanding on the behaviour of pipes under the loads from**ground movements. The test program will consists of following: i) axial pullout testing of plane pipes; ii) axial**pullout testing of pipes with Tee-junctions (branched pipes); and iii) lateral pullout testing for pipes, buried in**loose and dense sand. Laboratory element testing will be conducted to find geotechnical parameters and**development of constitutive models for sand and the strain rate dependent behavior of MDPE pipe materials.**FE modelling techniques will be developed using Abaqus FE software to simulate the observed response from**the full-scale pipe tests. The findings from this research will be useful to the Canadian pipeline industry,**enabling them to assess pipeline conditions in unstable ground and thus to make more effective management**decisions to ensure structural integrity of the pipeline and minimize the risk of pipeline failure.

管道将液体和气体从源头输送到**用户，在现代社会中发挥着重要作用。据加拿大自然资源部称，大约825,000公里的石油和天然气输送、集输**和分配管道穿越加拿大。许多这些管道穿过容易发生山体滑坡的区域。**山体滑坡引起的土壤移动可能会对管道造成纵向、横向或组合载荷**，具体取决于管道相对于移动地面的方向。滑坡地区管道结构完整性评估的现有设计**指南是根据对刚性管道的观察而制定的，可能不适用于柔性管道，例如中密度**聚乙烯（MDPE）管道。然而，包括 MDPE 管在内的柔性聚乙烯管由于其各种优点，在过去几十年中得到了广泛的应用。用于评估滑坡荷载下 MDPE 管道性能的设计方法尚不成熟。 MDPE 的全尺寸测试和有限元 (FE) 建模也非常有限。在拟议的研究中，将使用纽芬兰纪念大学**（MUN）的设施对**小直径 MDPE 管道进行一系列全面测试，以开发数据库并更好地了解管道在来自**地面运动的负载。试验计划包括以下内容： i) 平面管的轴向拉拔试验； ii) 带 T 形接头的管道（支管）的轴向**拉拔测试； iii) 埋在松散和致密沙子中的管道的横向拉拔测试。将进行实验室元素测试，以查找岩土参数并**开发沙子的本构模型以及 MDPE 管道材料的应变率相关行为。**将使用 Abaqus FE 软件开发有限元建模技术，以模拟观察到的响应**全尺寸管道测试。这项研究的结果将对加拿大管道行业有用，**使他们能够评估不稳定地面的管道状况，从而做出更有效的管理**决策，以确保管道的结构完整性并最大限度地降低管道故障的风险。