The effect of internal pressure on the longitudinal behaviour of pipelines

管道是石油和天然气从资源所在地到炼油厂的最重要的运输方式之一。他们是加拿大经济的重要组成部分。为了实现其设计目标，管道必须安全地输送高压易燃物质。在这样做时，管道需要承受由于内部压力引起的周向应力和由外部载荷引起的纵向应力的组合。这些外部荷载主要是土壤移动和温度影响的结果，两者都是由加拿大恶劣的环境引起的。由于管道穿越加拿大各地丰富的不连续永久冻土区，它会受到因季节温差大而加剧的不均匀沉降，从而引起较大的纵向应力。此外，管道通常需要穿过各种水路和道路以及变化的表面地形。这些位置可能会有纵向管道变形的集中，认为它们对于安全的管道设计非常关键。本提案涉及加拿大现行设计指南中的三个方面，其中规范方程未考虑管道内部压力和纵向响应之间的相互作用。

Pipelines are one of the most important modes of transportation for oil and gas from the location of the resources to the refineries. They constitute an influential part of the Canadian economy. To achieve their design objective, pipelines have to safely transport a highly pressurized flammable substance. In doing so, pipelines need to sustain a combination of circumferential stresses due to the internal pressure and longitudinal stresses induced by external loads. These external loads are primarily the result of soil movement and temperature effects, both induced by the harsh Canadian environment. As the pipe traverses areas of discontinuous permafrost abundant throughout Canada, it is subjected to differential settlement exacerbated by the large seasonal temperature differential which induces large longitudinal stresses. In addition, the pipelines are usually required to cross various water and road ways as well as varying surface topography. The locations of these can potentially have a concentration of longitudinal pipe deformation deeming them very critical for a safe pipeline design. This proposal addresses three areas in the current Canadian design guidelines in which the code equations do not consider the interaction between the internal pressure and the longitudinal response of the pipeline.