堆载对埋地输气管道受力的影响及安全性评价方法研究

发布时间：2018-04-24 22:34

本文选题：地面堆载 + 埋地输气管道　；参考：《成都理工大学》2017年硕士论文

【摘要】：管道运输是能源输送的一种较为安全快捷的运输方式,在国民经济中占有很大的比例,因此油气管道工程已经成为国家战略工程建设的重要组成部分。管道建成后,在运营期间受到管道途经地域的自然因素与人为因素的影响,外部条件不可避免会发生变化,如管道附近的堆载就十分常见,堆载势必引起管道发生变形与应力改变,当这种应力与变形超过管道的承受范围时,管道就会发生灾害性破坏,并由此引发事故,造成人民生命财产的损失与环境的破坏。因此,研究堆载作用对于埋地输气管道的影响,对于保障输气管道的运营安全具有十分重要的指导作用和实用价值。本文通过对堆载作用下埋地输气管道的应力、变形进行分析,运用三维数值模拟软件ABAQUS分析了堆载作用下,埋地输气管道的主要影响因素,对管道进行了详细的应力分析,并运用敏感性分析方法得出了各影响因素间对管道的影响程度,进而得出了快速评价堆载作用下埋地输气管道安全性的评价方法,并通过现场大型堆载试验对该评价方法进行验证,获得了如下几点认识:(1)通过实例系统总结了堆载体对埋地输气管道的影响,分析了堆载条件下输气管道的受力特点,包括地基变形、管周土体压力及影响因素等,在堆载作用下,管道表面应力与变形呈现明显的规律性。(2)通过现场试验与数值模拟对比分析验证了数值模拟的可行性。据此,运用大型有限元软件ABAQUS建立堆载作用下的管道与地基土体模型,通过对堆载作用下输气管道的力学性状分析,提出了堆载距离、堆载高度、管道埋深、泊松比等对输气管道不同的影响程度,随着堆载间距的减小,以及堆载高度、管道埋深和泊松比的增大,管道表面应力逐渐增大。(3)通过对堆载作用下埋地输气管道的影响因素进行敏感性分析,认为泊松比对管道表面应力影响最大,其次为管道埋深、堆载间距和堆载高度。(4)分析了埋地输气管道的附加应力与各影响因素之间的关系,获取了它们之间的关系表达式,获得了快速评价堆载作用下埋地输气管道安全性的重要方法,给出了相应的评价流程。(5)结合华阳现场大型堆载试验、简阳天然气管道残余应力检测试验、龙泉驿天然气管道残余应力检测试验,充分验证了堆载作用下埋地输气管道安全性快速评价方法的可靠性。(6)针对堆载作用下埋地输气管道存在的风险,研究并提出了5项基本保护措施,为提高输气管道的安全提供了重要参考。
[Abstract]:Pipeline transportation is a safe and fast transportation mode of energy transmission, which occupies a large proportion in the national economy. Therefore, oil and gas pipeline engineering has become an important part of national strategic engineering construction. After the pipeline is completed, it is affected by the natural and human factors of the pipeline passing through the area during operation, so the external conditions will inevitably change, such as the heaped load near the pipeline is very common. Heaped load is bound to cause pipeline deformation and stress change. When this kind of stress and deformation exceed the bearing range of pipeline, the pipeline will be damaged, which will lead to accidents, resulting in the loss of life and property of the people and the destruction of the environment. Therefore, it is of great importance and practical value to study the influence of heaps on buried gas pipelines and to ensure the safety of gas pipelines. In this paper, the stress and deformation of buried gas pipeline under heaped load are analyzed, and the main influencing factors of buried gas pipeline under heaped load are analyzed by using three-dimensional numerical simulation software ABAQUS, and the stress of pipeline is analyzed in detail. The sensitivity analysis method is used to get the degree of influence on pipeline, and the method to evaluate the safety of buried gas pipeline under the action of heaped load is obtained. The evaluation method is verified by large-scale surcharge test in the field, and some understandings are obtained as follows: (1) through an example, the influence of heap carrier on buried gas pipeline is systematically summarized, and the mechanical characteristics of gas pipeline under heaped load are analyzed. Including foundation deformation, soil pressure around pipe and influencing factors, under the action of surcharge, the surface stress and deformation of pipeline show obvious regularity. The feasibility of numerical simulation is verified by field test and numerical simulation. Based on this, a large-scale finite element software ABAQUS is used to establish the model of pipeline and foundation soil under heaped load. By analyzing the mechanical properties of gas pipeline under the action of heaped load, the paper puts forward the surcharge distance, height of heaped load and buried depth of pipeline. Poisson's ratio has different influence on gas transmission pipeline. With the decrease of heap-load spacing and the height of heaped load, the buried depth and Poisson's ratio of pipeline increase. Based on the sensitivity analysis of the influence factors of buried gas pipeline under the surcharge, it is concluded that Poisson's ratio has the greatest influence on the surface stress of the pipeline, followed by the buried depth of the pipeline. The relationship between the additional stress of buried gas pipeline and the influencing factors is analyzed, the expression of the relationship between them is obtained, and an important method to quickly evaluate the safety of buried gas pipeline under the action of surcharge is obtained. The corresponding evaluation flow. 5) combined with Huayang large-scale surcharge test, Jianyang natural gas pipeline residual stress detection test, Longquanyi natural gas pipeline residual stress detection test, The reliability of the fast evaluation method for the safety of buried gas pipelines under the action of heaps is fully verified. (6) in view of the risks of buried gas pipelines under the action of heaped loads, five basic protective measures are studied and put forward. It provides an important reference for improving the safety of gas transmission pipeline.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE973

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