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。它们构成了加拿大经济中有影响力的一部分。为了实现设计目标，管道必须安全地运输一种高度加压的易燃物质。在这样做的过程中，管道需要承受由于内部压力而产生的周向应力和外部载荷引起的纵向应力的组合。这些外部环境负荷主要是土壤运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。由于管道横跨加拿大各地不连续的多年冻土丰富的地区，它受到不均匀沉降的影响，这一差异因巨大的季节性温差而加剧，从而产生较大的纵向应力。此外，这些管道通常需要穿越各种水路和道路，以及不同的地表地形。这些管道的位置可能会有高度集中的纵向管道变形，因此它们对于非常安全的管道设计非常关键。这项建议还解决了目前加拿大设计指南中的三个方面，在这些方面，规范方程没有考虑管道的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.