海底管线水平向屈曲过程中管土相互作用研究-岩土工程专业论文.docxVIP

摘 摘 要 在高温高压状态下运行的海底管线会面临屈曲剧变问题，而地基土体对管线 的约束作用是制约管线屈曲的重要原因。研究表明地基土对管线作用力的大小决 定着管线发生屈曲变形的形态。因此，地基土体对管线的抗力成为管线屈曲剧变 问题研究的重要内容。本文通过模型试验、理论分析和有限元模拟对管线发生水 平向和轴向变形时土体抗力的发挥过程及土抗力峰值进行了系统研究。 结合渤海湾土质特点，分别选取细砂和粘土进行了室内管土相互作用模型试 验，研究不同直径、不同埋深情况下管线水平向运动以及轴向运动时土体抗力的 发挥过程。通过对试验结果的分析，得到了管线在运动过程中土体抗力随位移变 化的规律，以及管径、埋深等因素对管线受到的土体抗力峰值的影响并分析了土 体的破坏模式。 以试验数据为基础，对管线发生水平向和轴向位移时受到的土体抗力进行了 理论研究，推导并提出了适于计算渤海湾砂土和粘土地基对埋设管线抗力峰值的 经验公式。 在理论分析的基础上，进一步应用有限元软件对模型试验进行了模拟分析， 将得到的分析结果与试验结果进行了比较，进而模拟了渤海中常用的12英寸管 线水平向和轴向运动时土体抗力的发挥过程，与理论计算结果进行了比较，建立 了适用于描述砂土和粘土变形与受力特性的弹簧模型。 通过以上研究，为温度应力作用下海底管线发生水平向屈曲剧变研究提供了 数据基础。 ： 关键词：海底管线水平向屈曲管土相互作用模型试验有限元分析 ■ ABSTRACTIn ABSTRACT In service submarine pipeline under high temperature and pressure often occurs lateral buckling，while the restraint of foundation soil to the pipeline is the main factor to prevent this from happening．Studies show that the configuration of the buckling is determined by size of this restraint．So，the resistance of foundation soil to the pipeline is the most important point in the study of lateral buckling．In this paper,the process of how resistance works and its peak value when the pipeline does lateral and ^ axial movements are systematically studied through model tests，theoretical analysis ▲ and finite element simulation． 、 Combining properties of soil in Bohai Gulf,fine sand and clay were selected tO do indoor model tests to study how the resistance works when the pipeline with different diameters and depths of bury do lateral and axial movements．By analyzing the test results，regularity of the relationship between soil resistance and displacement and impacts of factors such as diameters and depths of bury etc．on peak value and failure modes werc obtained． Calculation method of peak value of soil resistance when the pipeline does lateral and axial movement was theoretically studied and deduced as well．What’S more，based on test data，empirical formula to calculate peak value of soil resistance that foundation soil tO the pipeline suitable for sand a