水毁灾害作用下腐蚀缺陷管道的力学行为分析与可靠性模型研究

发布时间：2018-11-04 14:19

【摘要】：中国的油气管道正面临着各种地质灾害和人为活动的双重威胁,油气管道的安全直接关系着中国能源运输的安全,因此管道的安全问题是亟待解决的关键性问题。通过查阅文献资料和调查近年来国内外管道事故案例,发现水毁地质灾害是威胁在役管道安全的关键因素之一。本文通过查阅各种资料,结合管道工程中所遇到的实际问题,首先分析了油气管道运输目前的安全、经济、技术等状况。然后结合中国西南片区油气管道的调查结果,查阅已有的成果资料,根据常用的方法将管道水毁的情况进行了识别分类,得出了按照各种分类规则划分后的管道水毁识别分类表。结合管道水毁的分类结果,本文进一步阐释了管道水毁的诱发原因及管道水毁的作用形式。除此以外,本文根据兰成渝管道中德阳石亭江段水毁导致管道悬空380米的实际案例,查阅管材资料、土体参数、水毁作用力等情况,利用大型有限元软件Abaqus建立管道-土体作用模型,首先验证了管道悬空案例中的极限悬空长度可达436米。然后建立径厚比均为100:1的管道悬空的数值分析模型,模拟计算得出了径厚比都为100:1的情况下,不同管径的管道的极限悬空长度。最后本文研究了带腐蚀缺陷管道的极限悬空长度情况并建立了带腐蚀缺陷管道悬空长度的极限状态方程。具体的完成步骤如下:(1)收集管道腐蚀的资料,确定研究的管道腐蚀坑的形状为长方体。(2)分别建立了腐蚀坑位于悬空管道管端和位于管道跨中的模型,并且分别考虑腐蚀坑的深度、宽度、长度等因素对管道极限悬空长度的影响,绘制出深度影响极限悬空长度的曲线、宽度影响极限悬空长度的曲线、长度影响极限悬空长度的曲线、腐蚀坑影响管道最大位移的曲线。(3)结合到腐蚀坑对管道极限悬空长度的影响以及各影响因素间的关系,建立管道悬空长度的极限状态方程。并介绍了计算失效概率及可靠度的常用方法。本文主要结论有:(1)分别建立了按成灾原因、动力介质及发生部位、管道穿越地形、水毁机理及水毁地形、水毁规模来划分的管道水毁识别分类表,并根据划分结果,分析了地质情况、降水情况、人工活动这三方面原因对管道水毁灾害的影响。(2)当径厚比为100:1且管径大于530毫米时,管道的极限悬空长度随管径的增加而保持不变。(3)腐蚀坑的位置对管道极限悬空长度影响较大,且腐蚀坑在管端时影响最大。(4)带腐蚀缺陷管道的极限悬空长度随腐蚀深度增加而减小。(5)带腐蚀缺陷管道的极限悬空长度随腐蚀宽度加而减小。(6)腐蚀坑长度对管道极限悬空长度影响很小。(7)腐蚀缺陷的长度、深度、宽度对管道的最大位移影响很小。(8)建立了带腐蚀缺陷管道的极限状态方程、并求解可靠度。
[Abstract]:Oil and gas pipelines in China are facing the double threats of geological hazards and man-made activities. The safety of oil and gas pipelines is directly related to the safety of energy transportation in China, so the safety of pipelines is a key problem to be solved. By consulting the literature and investigating the cases of pipeline accidents at home and abroad in recent years, it is found that the geological disaster of water damage is one of the key factors threatening the safety of existing pipelines. By referring to all kinds of data and combining with the practical problems encountered in pipeline engineering, this paper first analyzes the present safety, economic and technical situation of oil and gas pipeline transportation. Then according to the investigation results of oil and gas pipelines in southwestern China, looking up the existing achievements and classifying the water damage of pipelines according to the commonly used methods, The classification table of pipeline water damage recognition is obtained according to various classification rules. Combined with the classification results of pipeline water damage, this paper further explains the cause of pipeline water damage and the action form of pipeline water damage. In addition, according to the actual cases of water destruction in Shiting reach of Deyang in Lancheng and Chongqing pipeline, which resulted in the pipeline suspended 380 meters, the paper consulted the data of pipe material, soil parameters, water damage force and so on. The finite element software Abaqus is used to establish the pipe-soil interaction model. Firstly, it is verified that the limit suspension length in the case of pipeline suspension can reach 436m. Then, a numerical analysis model for the suspension of pipes with diameter to thickness ratio of 100: 1 is established, and the maximum suspended length of pipes with different diameters is obtained when the ratio of diameter to thickness is 100: 1. Finally, the limit suspension length of the pipeline with corrosion defect is studied and the limit state equation of suspension length of the pipeline with corrosion defect is established. The specific completion steps are as follows: (1) collecting the data of pipeline corrosion, determining the shape of the corrosion pit of the pipeline studied as cuboid. (2) establishing the model of corrosion pit located at the end of suspended pipe and in the middle of pipeline span, respectively. Considering the influence of the depth, width and length of the corrosion pit on the limit suspension length of pipeline, the curve of the depth affecting the limit suspension length and the curve of width affecting the limit suspension length are drawn. The curve of the limit suspension length is affected by the length of the corrosion pit, and the curve of the maximum displacement of the pipe is affected by the corrosion pit. (3) the influence of the corrosion pit on the limit suspended length of the pipeline and the relationship between the factors affecting it, The limit state equation of pipeline suspension length is established. Common methods for calculating failure probability and reliability are also introduced. The main conclusions of this paper are as follows: (1) the classification table of pipeline water damage is established according to the cause of the disaster, the dynamic medium and the location of the disaster, the pipeline crossing terrain, the mechanism of water destruction and the water destruction terrain, and the scale of water destruction, and according to the results of the classification. The influence of geological condition, precipitation condition and artificial activity on pipeline water damage disaster is analyzed. (2) when the diameter to thickness ratio is 100: 1 and the diameter of pipe is more than 530 mm, The ultimate suspended length of pipeline remains constant with the increase of pipe diameter. (3) the location of corrosion pits has a great influence on the ultimate suspended length of pipeline. (4) the limit suspension length of pipeline with corrosion defect decreases with the increase of corrosion depth, and (5) the limit suspension length of pipeline with corrosion defect decreases with the increase of corrosion width. The length of corrosion pit has little effect on the limit suspension length of pipeline. (7) the length of corrosion defect, The depth and width have little effect on the maximum displacement of pipeline. (8) the limit state equation of pipeline with corrosion defect is established and the reliability is solved.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE988.2

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