【作者】 王沪毅；

【导师】 王峰会；

【作者基本信息】 西北工业大学 ， 固体力学， 2003， 硕士

【摘要】 在西气东输工程中，有一大部分管线要穿越黄土高原。由于黄土高原的特殊地质条件，容易发生坍塌、冲沟和滑坡等地质灾害。这些灾害使得管线发生变形和失效，造成重大事故，发生人员伤亡和重大的经济损失。因而，研究黄土地质灾害对管道的破坏的力学行为具有重要的工程意义。 本论文是一个涉及到地质力学、土力学和固体力学的交叉学科的研究，运用了土力学、弹性力学和有限元方法对管道在地质灾害中的侵害进行了建模和计算。得到的主要结果为： (1)基于弹性地基理论和弹性梁的挠曲线理论，给出了管道在固定墩(相当跨越河沟情况)和无固定墩(相当坍塌和冲沟情况)的变形微分方程，并分析了当量轴力为拉力或压力时管道的变形和受力情况。 (2)以Winkler线形地基模型为基础，确定无固定墩管道两端的地基反力，并考虑黄土的内聚力作用，计算了不同长度黄土坍塌发生时管道的受力和变形，给出了管道上应力场的分布和最大Mises应力部位。确定了管道的失效长度。计算了冲沟发生时对无固定墩管道的影响。另外计算了有固定墩管道在坍塌和冲沟发生时的失效长度。 (3)基于Ranken土压力理论，分析建立了土—管道的相互作用模型。模型中考虑了管道上方土的作用，管道自身的重量、气体的压力和自重以及滑坡时管道下方土的压力和土与管道的摩擦力。采用有限元方法按接触问题进行计算，得出了不同坡度、不同长度的滑坡发生时管道的应力分布，确定了最大Mises应力发生的部位和失效长度。并提出了防治的措施。 (4)采用预缺陷的方法，模拟管道受力情况，初步计算了管道在同时受到内压和拉／压力时的失稳问题。从计算的结果看，在缺陷处的应力有突变，该处的变形较大，是失稳容易发生的部位。更多还原

【Abstract】 In the project of energy transportation from the west to the east, pipelines cross the loess altiplano. Because of its special land conditions, there are a lot of disasters, such as collapse, gulch and landslide. They occur frequently. They cause pipeline to be distorted or destroyed, and they will bring a lot of loss. So it is very important to study the of pipelines.The paper studies pipelines behaviors by geomechanics , soil and solid mechanics. And compute the created model by the way of FEM. And results are:(1) analyze the force and distortion on pipeline under collapse and gulch in theory. On the base of beam deformation, analyze the bending moment and deformation of pipeline with frusta and without frusta. Calculate a true problem, contrast the differences between pipeline with frusta and one without frusta , draw some conclusions.(2) on the base of Winkler model, compute the anti-forces of pipeline without frusta, considering the loess cohesion. Compute the distortion and force of pipeline under different length of collapse. And get the stress field and the greatest Mises stress and its location.(3) on the base of Ranken theory, analyze the soil-line model. In the model, they are considered, soil effect up and under line, line weight, gas pressure and its weight. By the way of FEM, we get the stress field and he greatest Mises stress and its location under different landslide conditions.(4) simulate the buckling condition of pipeline by pre- disfigure. Compute the force in pipeline under inner pressure and coaxial forces. And get the conclusion that there is abrupt change of stress in the defect location. So it’s the position easy to be buckling.更多还原