Novel Computational Nonlinear Analysis of Soil-Pipe Interaction under Large Displacement in Geo-Hazard Environment: a Preliminary Study

尽管经过几十年的研发，油气管道的故障仍然不可避免。对管道力学应力和变形的新认识将有助于改进管道的设计和施工，从而减少管道的失效。我们关注地质灾害环境中管道的安全，例如加拿大北部的深层穆斯凯克，并决心了解艾伯塔省最近发生的管道破裂事件。不稳定的土壤条件，如滑坡和地下水压力的变化，会在这些管道中产生过多的应力和挠曲，这可能比已知的对结构完整性更危险。 该项目的创新之处在于利用三维计算机模拟土-管相互作用的大位移，这在管道设计中目前还没有进行，因为分析非常具有挑战性，因为管道的大挠度，管道与周围土壤之间的大滑动，以及土壤固结和地下水压力的波动。由于缺乏有效的分析工具，管道的设计往往要么风险很高，要么过于保守。通过我们的案例研究，我们将更好地了解管道的完整性，这些案例通过计算模拟恶劣环境中的危险载荷和位移条件。 该项目与加拿大压力工程服务部合作，将开发一种有效的工具，用于加强地质灾害环境中管道的安全设计，并在环境发生变化时对安装的管道进行安全评估。该工具将用于正在进行的加拿大管道项目，这些项目将促进艾伯塔省和加拿大的经济发展，同时保护环境。

Despite decades of research and development, oil and gas pipeline failures are still inevitable. New understanding in the mechanical stress and deformation of the pipeline will help improve pipeline design and construction and therefore reduce pipeline failures. We are concerned with the safety of pipelines in geo-hazard environments such as deep muskegs in northern Canada, and are determined to understand the most recent pipeline rupture in Alberta. Unstable soil conditions, such as landslides and ground water pressure changes, produce excess stress and deflection in these pipelines, which may be more dangerous to the structural integrity than what is known. The novelty of this project is the use of three dimensional computer modelling of large displacement of the soil-pipe interaction, which is not currently performed in the pipeline design because the analysis is very challenging with large deflection of the pipe, large sliding between the pipe and soil surrounding it, and soil consolidation with ground water pressure fluctuations. Due to lack of effective analysis tools, pipelines are often designed with either high risk or over conservatively. The integrity of the pipelines will be better understood with our case studies that computationally simulate hazardous loading and displacement conditions in harsh environments. This project collaborating with Stress Engineering Services Canada will lead to the development of an effective tool for enhanced safety designs of pipelines in geo-hazard environments and for the safety assessment of installed pipelines when environmental changes occur. The tool will be used in the ongoing Canadian Pipeline projects, which will promote economy and yet protect the environment in Alberta and Canada.