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题名	滑坡与输油气管道的力学机理与防治——以兰成渝输油管道为例
作者	马清文
学位类别	博士
答辩日期	2007
授予单位	中国科学院水利部成都山地灾害与环境研究所
授予地点	成都
导师	王成华
关键词	滑坡 长输油气管道 力学机理 室内模型实验 FLAC3D数值模拟 应力释放法 滑坡防治
学位专业	自然地理学
中文摘要	长输油气管道在山区的大量建设必然会遭遇到各种各样的地质灾害，其中滑坡就是对管道影响最为常见和严重的灾害之一，如不及时治理将会对管道造成较大的破坏，带来较大的经济损失。目前，滑坡启动机理或管道力学特性的研究均得到了很大发展，但对滑坡与输油气管道相互作用的力学机理的研究较少，尤其在管道对小型滑坡的加固作用、管道的不同敷设模式对破坏模式的影响、管道滑坡风险性评估、防治工程特殊性等方面的研究更少。本论文选取兰成渝输油管道为研究区，采用野外调查、力学分析、室内模型实验和数值模拟等方法，对滑坡与管道力学机理进行了深入研究。研究内容包括：管道沿线滑坡地质灾害特征调查，分析管道沿线滑坡的规模、类型、形成机理、危险程度等规律；管道在滑体中不同敷设方式下的受力变形分析；有/无固定墩时管道的受力、变形分析；管道在滑坡作用下的破坏判据；管道滑坡的防治工程技术。在以下几个方面得出了一些结论和成果：（1）管道沿线滑坡以小型为主，中型或大型滑坡较少；滑体物质主要为土质或碎石土滑坡，岩质滑坡很少；以薄层滑坡为多主，厚度一般较小，多为3～10m；滑坡产生原因多为工程不合理开挖和未及时支护引起的；滑坡灾害点较多，但单个滑坡对管道的危害程度较小。（2）影响管道滑坡稳定性的三个主要因素为：管道与滑坡的空间关系；管道的直径（管道承受滑坡推力的面积）；滑坡体物质组成。按照管道与滑坡敷设的空间关系（即管道敷设在滑坡体的部位，如埋设在滑坡后缘、前缘或中部，在滑动面上方或下方；垂直、平行或斜交滑坡主滑方向）的不同，探讨了管道受力破坏模式及管道滑坡失稳模式。以管道垂直滑坡主滑方向敷设在滑坡体中下部且位于滑动面以上时最为危险。（3）通过室内模型实验验证了管道对滑坡有加固作用，尤其当滑坡规模较小时，管道对滑坡的抗滑力作用相当明显。当管道两侧有固定墩时，管道提供的抗力较大，在管道上方易形成新的剪出口，滑体从管道上方剪出，当管道无固定墩时，提供的抗力较小，易随滑体一起移动，对滑动面的影响不大。（4）通过FLAC3D数值模拟，分析了周河滑坡在不同工况下的稳定性，并通过改变管道在滑坡体中的位置、管道强度和有/无固定墩三个方面研究滑坡与管道的相互作用。据模拟分析，周河滑坡目前处于轻微变形期，如自然条件进一步恶化（如遭遇50年一遇降雨），坡体变形将加大，形成贯通滑动面，滑坡整体失稳，管道破坏。管道埋设在滑体中下部时以受压破坏为主，在中上部时以管道自重形成的悬空破坏为主。管道强度变化会影响滑动面的位置。（5）结合室内模型实验及数值模拟结果，根据管道敷设关系、有/无固定墩、土壤抗力大小三个方面，对滑坡与管道作用的力学模型进行简化，并分别进行计算，得出最大弯距和扰度的公式，为管道滑坡危险性评估和监测提供了理论依据，并得出了管道变形破坏的两个判据：力的判据和位移判据。（6）固定墩不应限制管道轴向变形。固定墩在未破坏前对滑坡有较大的稳定作用，一旦破坏会把滑坡的力传递给管道，反而对管道稳定不利。（7）针对管道滑坡的特殊性，给出了针对小型管道滑坡的治理方案，包括管道敷设前的选线原则，敷设后的风险性评估指标选取，管道滑坡变形监测措施以及对应的防治方案。（8）提出应力释放法治理管道沿线滑坡的方法，即通过开挖一定深度的管沟，释放滑坡应力，或形成新的滑动面，通过室内模型实验及数值模拟，证明该方案是可行的，开挖深度应不小于该处滑面埋深的2/3，开挖宽度应满足管道上方坡体变形要求。本文的创新点在于得出了长输油气管道沿线滑坡的规模、形成原因、分布规律、危害程度等基本规律，并按照管道敷设模式进行分类，通过室内模型实验和数值模拟研究了管道破坏模式以及与滑坡作用的力学机理，得出了管道变形破坏的两个判据，为油气管道沿线滑坡防治提供理论依据。值得一提的是，本文比较系统地提出了治理管道滑坡的新方法——应力释放法，并通过室内模型实验和数值模拟进行了验证。
英文摘要	With the development of the long distance gas and oil pipeline in mountain area, there are many kinds of geological hazards along those pipelines and landslides are the most common and serious. The pipeline will be destroyed if the landslides did not be controlled in time, which accompanies great economic losses. Now, the researches on dynamical mechanism of landslide and analysis of pipeline have been developing more perfectly. But the analysis on the dynamical coupling mechanism between landslides and pipelines is little studied. The researches on the pipeline reinforcing, different destroying mode resulting from different laying mode of pipeline, risk evaluation and the character of control technology are much less.Based on the investigations on the Lan-Cheng-Yu oil and gas pipeline, the methods including field investigation, dynamical analysis, physical simulation experiments and numerical simulation are adopted to research the dynamical mechanism between landslides and pipelines further. The contents in the paper include: investigations on landslide geological hazard, analysis on the rules of the landslide dimension, type, formation mechanism and the classification of hazard degree along the pipeline, mechanical and deforming analysis on the pipeline laid in different mode and whether there are fixed frusta or not, failure criteria of pipeline and the control technology of pipeline landslide. The main conclusions and results can be expressed as follows:(1) The main type of landside in this area is small scaled landslide, and the big or middle landslide is less. The matters of landslide are mainly soils or gravels, rocks seldom. The thin landslides predominate, often 3~10m thick. Causes of the landslide are mainly the irrational digging and without timely support of slope. The landslide hazards distribute widely, but their hazardous degree is lower.(2) Three main factors which affect the stability of pipeline are as follows: the spatial relation between pipelines and landslides, the pipeline diameter (the area of pipeline bearing slide force), and the composition of the landslide. The failure modes of pipeline and the landslide are studied respectively according to the laying mode of pipeline. The pipeline positions include the back, front or middle of the landslide; under or over of the slide plane; perpendicular, paralleling or gradient intersecting to the main slide direction. It is most dangerous when the pipeline is laid in the middle and underside and perpendicular to the main slide direction of landslide.(3) It is proved that pipeline has the locking effect to the landslide based on the physical simulation experiments, especially when the landslide is little. The anti-sliding forces are comparatively evident and the pipeline can stabilize the landslide when there are fixed frusta. It is easy to form the new slide plane, and the matters of landslide are apt to glide from the upside of pipeline. When there is not fixed frusta the anti-sliding forces is little and the pipeline will slide with the matters of landslide.(4) Based on FLAC3D numerical simulation, the stability of Zhouhe pipeline landslide is analyzed in different engineering condition. The coupling relation between the pipeline and landslide is studied by changing the position of the pipeline in the landslide, the strength of pipeline and the fixed condition. Now, the Zhouhe landslide is under the preliminary deforming stage. Once the nature condition is worse, the landslide will slide in whole and the pipeline will be ruptured. The pipeline is destroyed by the slide forces when the pipeline is laid in the middle or front of landslide. However, it will be destroyed by the self weight when the pipeline is laid over the landslide. The position of the slide plane will change with the change of pipeline strength.(5) Combining with the results of physical and numerical simulation, the dynamical mode is simplified in relation to the laying mode of pipeline, fixed frusta and anti-forces of soil. Quotations of maximum moment and displacement are favor to the hazardous investment and the survey of landslide. At the same time, dynamical analysis of pipeline and landslide is confirmed. The two failure criterias of pipeline, force and displacement, are put forward by the dynamical analysis.(6) The fixed frusta should not be restricted the distortion of the pipeline. When the fixed frusta are not destroyed by the landslide, it can help to stabilize the landslide. Once it is destroyed, the fixed frusta are unfavorable to the landslide because the fixed frusta become the area of stress concentration.(7) In view of the pipeline particularity, the system of prevention and treatment of pipeline landslide is brought forward. The paper provide the treatment plan for the minitype landslide, which include the criterion of route selection before laying the pipeline, the choice of the indicator of risk evaluation after laying the pipeline, how to monitor the landslide deforming and corresponding prevention and treatment plane.(8) The Stress-relief method is provided in the paper, which is excavating a ditch with certain depth to release the stress or form the new slide plane. Based on the physical and numerical simulation, the feasibility of the plan is proved. The digging depth should be not less than the 2/3 depths of slide plane, and the width should meet the deforming need of over soils.The innovations in the paper are the following: finding the rules of the dimension, type, formation mechanism, distribution and hazard degree of landslides along the long distance gas and oil pipeline, classification of landslide according to the different pipeline laying mode. The destroying mode and dynamical mechanics of pipeline under landslide provides theoretical foundation for preventing and curing landslide along the pipeline. Especially, the Stress-relief method, as a new method to control landslide, is provided systematically and proved by the physical and numerical simulation.
语种	中文
学科主题	灾害学
公开日期	2010-10-21
分类号	X92;TE4
内容类型	学位论文
源URL	[http://ir.imde.ac.cn/handle/131551/2281]
专题	成都山地灾害与环境研究所_成都山地所知识仓储（2009年以前）
推荐引用方式 GB/T 7714	马清文. 滑坡与输油气管道的力学机理与防治——以兰成渝输油管道为例[D]. 成都. 中国科学院水利部成都山地灾害与环境研究所. 2007.

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