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.

管道通过将液体和气体从来源运送到**用户中在现代社会中发挥着重要作用。根据加拿大自然资源的说法，大约825,000公里的石油和天然气传输，聚集**和分销管道加拿大。这些管道中的许多管道穿过容易发生滑坡的区域。**由于滑坡引起的土壤运动可能会在管道上引起纵向，横向或组合载荷，**根据管道相对于移动地面的方向。基于“刚体管道的**观察结果”，开发了对汇轮区域中管道结构完整性评估的现有设计**指南，该观察结果可能不适用于柔性管道，例如中密度**聚乙烯（MDPE）管道。但是，由于其各种优势，在过去几十年中，包括MDPE管道在内的柔性聚乙烯管已被广泛使用。评估经受压倒性载荷的MDPE管道性能的设计方法尚未得到充分发达。 MDPE的全尺度测试和有限**元素（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）的设施进行一系列**小直径MDPE管的全面测试，以开发数据库，​​并提高对**地面运动负载下管道行为的了解。测试程序将包括以下内容：i）平面管道的轴向拔出测试； ii）轴向**带有TEE-JUCTIONS的管道的拉动测试（分支管道）； iii）对管道的横向拉动测试，被埋在**松散且密集的沙子中。将进行实验室元素测试，以找到岩土参数和**用于沙子的组成型模型以及MDPE管道材料的应变率依赖性行为。这项研究的发现将对加拿大管道行业有用，**使他们能够以不稳定的地面评估管道条件，从而做出更有效的管理**决定，以确保管道的结构完整性，并最大程度地减少管道故障的风险。