近断层地震作用下悬跨海底管线响应研究

发布时间：2017-12-27 02:10

本文关键词：近断层地震作用下悬跨海底管线响应研究　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着现代化工业的不断推进,油气资源的供需矛盾日益突出,而海底管线作为海底油气运输最高效、最经济、最安全的方式,已成为工业化进程中的重要命脉,也是油气的开采系统和储存系统的重要组成部分。然而近几年来,关于海底管线泄油事件频发,海底管线的安全性与可靠性也日益得到重视。尤其我国处在地震多发带,地震对于管线的破坏所带来的损失更是无法预估与弥补,建立安全的管线抗震机制必不可少。关于地震对于海底管线的响应国内外均已有大量的研究。然而就近断层地震对于悬跨海底管线的响应较为有限。因此本文主要针对近断层地震作用下悬跨海底管线的响应进行研究。目前主要把距离断裂破裂面小于20km的区域看作近断层区域,近断层地震明显区别于远断层地震在于其特有的速度脉冲效应,一开始的大幅值脉冲便会给结构造成永久的破坏,尤其是对长周期结构具有更强的破坏性。本文在关于近断层地震已有研究的基础上,选取了台湾集集地震(1999年9月21日,震级MW=7.6)中的方向性效应、滑冲效应和远断层效应作为地震动输入,作用在管线上的动水力通过推导的Morrison方程以附加质量的形式作用在管线上,利用有限元大型软件ANSYS建立了悬跨海底管线的数值分析模型,该模型考虑了管线和土体的本构关系。据此,在三种地震效应作用下对悬跨海底管线进行了按水平方向一致输入的地震时程分析,结果发现对于管线应采用非线性模型。在此基础上,分别考虑了不同地震强度和不同自振周期下管线的非线性动力响应,并就三种地震效应下管线的响应进行了对比分析。通过对比分析发现,相比于远断层地震近断层地震效应对悬跨海底管线具有更显著的影响,尤其对于具有长周期的悬跨海底管线具有更强的破坏性。由于实际地震输入是多维的,为了找出对于悬跨海底管线最不利的地震动输入方向,分别选取了具有六种不同的方向作为地震动输入方向,首先就三种地震效应沿各个方向的地震输入下管线的动力响应进行了分析对比,计算表明对于不同的输入方向,三种地震效应下管线响应具有基本相同的响应规律。对不同方向地震动输入下进一步比较发现,当地震动分别沿X轴和Y轴的方向进行输入时管线具有最小和最大响应。最后对不同平面内不同角度的地震动输入下三种地震效应对于管线响应进行了比较。
[Abstract]:With the modernization of industry unceasing advancement, the contradiction between supply and demand of oil and gas resources have become increasingly prominent, and the sea transportation of oil and gas pipeline as the most efficient, most economical and safe way, has become an important lifeline in the process of industrialization, and it is also an important part of oil and gas exploitation system and storage system. However, over the past few years, the safety and reliability of submarine pipelines have been paid more and more attention to the frequent occurrence of oil discharge in submarine pipelines. Especially in China's earthquake prone area, the damage caused by earthquake damage to pipeline is unpredictable and compensated. It is essential to establish a safe pipeline anti-seismic mechanism. There has been a great deal of research on the response of earthquake to submarine pipelines both at home and abroad. However, the response of the near fault earthquake to the suspended submarine pipelines is limited. Therefore, this paper mainly studies the response of the submarine pipeline under the action of the near fault earthquake. At present the distance less than 20km fracture surface area as the near fault region, near fault earthquake is obviously different from the far fault earthquake lies in its unique effect of velocity pulse amplitude, a start pulse will cause permanent damage to the structure, especially for long period structure is more destructive. Based on the research on the existing earthquake near faults, selected the Taiwan Chi Chi earthquake (September 21, 1999, magnitude MW=7.6) directivity effect, the slip effect and far fault effect as seismic input in pipeline's hydrodynamic force through the derivation of the Morrison equation in the form of additional mass in the pipeline that established the numerical analysis model of submarine pipeline with large finite element software ANSYS, the model considers the constitutive relation of pipeline and soil. Based on this, the seismic time history analysis of the suspended submarine pipeline is carried out in horizontal direction under the action of three kinds of seismic effects. It is found that the nonlinear model should be adopted for pipelines. On this basis, the nonlinear dynamic responses of pipelines under different earthquake intensity and natural vibration period are considered respectively, and the responses of pipelines under three kinds of seismic effects are compared and analyzed. Through comparative analysis, it is found that the near fault seismic effect has a more significant impact on the suspended submarine pipeline than the far fault, especially for the long-span suspended submarine pipeline. Because of the actual seismic input is multidimensional, in order to find out the most unfavorable input direction of the submarine pipeline vibration, were selected with six different direction as seismic input direction, the first three kinds of seismic effect along each direction of earthquake input pipeline under the dynamic response of the calculation shows that for the input direction of the three earthquake under the effect of pipeline response has the same basic rule response. It is found that the pipeline has the minimum and maximum response when the local vibration is input along the direction of the X axis and the Y axis, respectively. In the end, three seismic effects under different angles of different angles are compared to the response of the pipeline.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P756.2

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