场地沉降条件下埋地输液管道损伤的简化模型研究

发布时间：2018-10-20 19:07

【摘要】：场地沉降条件下埋地输液管道的力学损伤分析,是研究埋地管道破坏机理和预防埋地管道事故发生的基础。所以埋地管道结构在大位移作用下的受力与变形等特性研究十分必要。因此对场地沉降条件下埋地输液管道损伤的研究分为三部分,即管道损伤的试验研究、数值模拟的对比分析以及建立相应的理论简化模型。通过场地沉降条件下埋地输液管道受力的试验研究,得出管道在沉降场地的变形曲线为三次函数曲线;当沉降区管道与下层土体分离时,最大轴向应变出现在沉降区中心;管径不同时对管道受力有影响,得出在相同条件下小管径的应力传递要快于大管径。管径越小轴向应变越大,越容易屈服。基于有限元分析软件ADINA,建立数值分析模型,对试验与模拟所得的管道变形曲线进行对比分析。随后建立不同沉降区长度、埋深、管径以及内压下的埋地管道数值模型,研究沉降范围的区分与沉降区长度等参数的关系。分析不同埋深和管径对管道最大轴向应变大小与出现位置的影响。得出非沉降区应变零点与管径的关系,以及内压对管道轴向应变影响。对非沉降区建立了弹性地基梁经典模型,推导非沉降区埋地管道的变形曲线函数关系。针对沉降区的类别与范围,分别建立了适于多种沉降场地的管道受力简化公式。最后得出判断管道受力损伤的应力破坏准则和应变破坏准则,以及管道的抵御沉陷能力的评价方法。
[Abstract]:The mechanical damage analysis of buried pipeline under the condition of site settlement is the basis of studying the failure mechanism of buried pipeline and preventing the accident of buried pipeline. So it is necessary to study the stress and deformation of buried pipeline structure under the action of large displacement. Therefore, the research on pipeline damage under site settlement is divided into three parts: experimental study of pipeline damage, comparative analysis of numerical simulation and establishment of corresponding theoretical simplified model. The deformation curve of pipeline in settlement site is cubic function curve, the maximum axial strain appears in the center of settlement zone when the pipeline is separated from the lower soil mass in settlement zone, the experimental study on the stress of buried pipeline under site settlement condition shows that the deformation curve of pipeline in settlement site is cubic function curve. The stress transfer of small diameter is faster than that of large diameter under the same conditions. The smaller the diameter of the tube, the larger the axial strain, the easier it is to yield. Based on the finite element analysis software ADINA, the numerical analysis model is established, and the pipeline deformation curves obtained by experiment and simulation are compared and analyzed. Then the numerical model of buried pipeline with different settlement zone length, buried depth, pipe diameter and internal pressure is established, and the relationship between the settlement range and the length of settlement zone is studied. The influence of different buried depths and pipe diameters on the maximum axial strain and location of the pipeline is analyzed. The relationship between strain zero point and pipe diameter and the influence of internal pressure on the axial strain of pipeline are obtained. The classical model of elastic foundation beam in non-settlement zone is established, and the function of deformation curve of buried pipeline in non-settlement area is deduced. According to the type and range of settlement area, the simplified formula of pipeline force is established for various settlement sites. Finally, the stress failure criterion and strain failure criterion are obtained to judge the pipeline stress damage, and the evaluation method of the pipeline's ability to resist the subsidence is obtained.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU433;U178

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