【作者】 刘慧；

【导师】 李昕；

【作者基本信息】 大连理工大学 ， 水工结构工程， 2008， 硕士

【摘要】 地震引发的滑坡是导致埋地管线破坏的重要原因之一,而埋地管线又是城市基础建设的重要组成部分,因此分析滑坡作用下埋地管线的反应规律是必要的。本论文通过对三种理想滑坡形式作用下的埋地管线进行理论分析,并与有限元数值结果进行验证,研究管线的反应规律,希望为今后埋地管线的抗震设计工作提供一些依据,主要包括以下几个方面:(1)在对已有研究成果总结的基础上,基于管土相互作用双线性模型,建立了轴向滑坡作用下管线的变形及应变分析模型,由有限元模型分析验证了公式的适用性,并得到一些有益的结论:土体下滑位移较大时,管线的最大轴向应变主要受滑坡长度控制;当滑坡长度较大时,管线的最大轴向应变受土体下滑位移控制。(2)基于理想弹塑性土体本构关系和弹性梁挠曲理论建立了埋管在有限宽横向滑坡和无限宽横向滑坡下的变形微分方程,其中考虑了管线由于大变形产生的轴向伸长对轴向应变的影响。得出管线在滑坡端5m附近的轴向应变为最大,大于20m宽度的滑坡与无限宽滑坡对管线的影响很接近。建立塑性管模型,模拟管线进入应力强化阶段时的反应,通过具体算例,定量分析了不同参数如滑坡宽度、土体下滑位移、埋深、管径等对管线反应的影响程度。根据计算结果得出管线的受力及变形的规律。(3)利用前面分析成果,把深层圆弧滑坡土体运动分解为轴向和横向分量,得到两分量下管线轴向应变,两者的相加值作为管线最大轴向应变的保守估计。并利用ANSYS计算出比较可靠的管线轴向应变。本文最后提出了埋地管线反应分析中需要进一步研究的问题和发展方向。更多还原

【Abstract】 Buried pipelines as one of part of lifeline are widely used to transport oil, gas, water, waste and so on. The landslide due to earthquake is one of the important factors resulted in damage and destroy of buried pipelines. Therefore, it is necessary to analyze the response of buried pipelines subjected to large ground deformation. Analytical solutions to three kinds of idealized landslide pattern under landslide are derived considering the interaction between soil and pipeline. Meanwhile, finite element models are established to validate the analytical solutions. Some conclusions can be drawn as the following:(1) On the basis of previous studying, a bilinear relationship related to deformation and force is introduced to simulate the soil and pipeline interaction and derive the analytical solutions to buried pipeline subjected to the longitudinal landslide. Compared with FE analysis, some results are obtained. If soil movement is large, the pipe strain is controlled by the length of the landslide. If the length of landslide is large, the pipe strain is dominated by soil movement.(2) Based on the perfectly elastic-plastic constitutive model of soil and the theory of elastic beam, differential equation of buried pipeline under finite width and infinite width transverse landslide is established. Axial strain is composed of bending strain and longitudinal strain due to large transverse deflection of the pipeline. The maximum axial strain is at the position of about 5 meters away from the boundary. The response of pipeline under the 20 m wide slope is almost equal to that of the one under infinitely wide slope. Then plastic pipeline model is proposed to simulate the pipe at the stage of stress strengthening. The effects of the width of landslide, the displacement of soil movement, the diameter of pipe and the buried depth are analyzed through an example.(3) According to the results above, the resultant soil movement with deep circular sliding is decomposed into two components such as parallel and perpendicular to the pipeline. The responses of the pipeline under two soil movement components are calculated respectively, and algebratic sum of maximum strain under each of component is defined as the total peak axial strain of the buried pipeline.The problems and future studying are suggested in the end of the paper.更多还原