长输油气管道沿线地理环境复杂，不可避免会穿越矿山采空区、湿陷黄土区、 山地滑坡区等不良地质区域，管道大跨度悬空变形、滑坡诱发管线断裂等安全事 故时有发生，造成重大人员伤亡和经济损失。开展地质灾害隐患区埋地油气管道 受力分析与风险评估研究，对于提升油气管网灾害预防管控水平、保障国家公共 安全具有重要的理论意义和工程实践意义。

       本文以埋地悬空管道、横向滑坡作用管道为研究对象，在弹塑性地基梁理论 框架下，分别建立悬空管道与滑坡管道管土耦合作用力学模型，发展高效管道模 型计算方法。在此基础上，引入动态时间规整技术，利用管体应变监测数据智能 辨识管周土体物力参数，构建由最大应力区、管道剩余承载力等指标构成的管道 灾害安全评价体系。主要研究内容及成果如下：

（1）建立油气管道管土耦合作用力学模型。根据悬空管道不同管段土体侧 向抗力响应特性，将管道划分为悬空段、塑性抗力段和弹性抗力段等三个区段， 基于弹塑性地基梁理论分区段建立管道挠曲控制方程，并结合边界条件和连续条 件给出求解埋地悬空管道挠度、轴力的定解条件；根据滑坡管道在逐渐增大的横 向滑坡推力作用下，管道侧向土体抗力所表现出的三种工况性态（弹性抗力工况、 塑性抗力且塑性区小于滑坡区工况、塑性抗力且塑性区大于滑坡区工况），基于 弹塑性地基梁理论分工况建立滑坡管道挠曲控制方程，并结合边界条件和连续条 件分别给出求解滑坡作用管道挠度、轴力的定解条件。

（2）提出求解管土耦合作用力学模型的高效计算方法。根据悬空管道和滑 坡管道的定解条件，推导出挠曲控制方程通解待定系数与管道轴力 T、塑性表征 长度 Δ 之间的显式表达式。采用遗传算法求解由 T、Δ 组成的非线性方程组，以 提高管土耦合模型求解精度和计算效率。算例分析表明，本文提出的半解析半数 值计算结果与有限元数值模拟吻合良好，可方便用于工程设计与安全评估。

（3）开展埋地悬空管道管周土体参数影响因素分析。基于悬空管道管土耦 合作用力学模型，结合实际案例，分析土体线性刚度、上覆土体对管道的垂直作 用力和悬空跨度对悬空管道的挠度曲线、弯矩和最大应变的影响。结果表明：悬 空跨度为影响管道受力的主控因素，当悬空跨度 L 超过 100m 时，悬空段外土体 将出现塑性，且塑性区随悬空跨度增加而扩大，如果不采用弹塑性模型，将会过 高估算管道应力分布。此外，管道最大应变恒定出现在距离悬空中心 1.02(L/2) 位置处，不随悬空跨度的变化而改变，宜作为管体应变传感器的重点布设区域。

（4）开展横向滑坡管道管周土体参数影响因素分析。基于滑坡管道管土耦 吴彬 硕士学位论文: 油气管道管土耦合分析方法与监测预警技术研究 II 合作用力学模型，结合实际案例，分析由滑坡推力 q0、土壤的线性刚度取 k、管 道外径 D 构成的无量纲参数 q0/kD、滑坡段宽度 L 对滑坡管道的挠度曲线、弯矩 和最大应变的影响。结果表明：滑坡段宽度为影响管道受力的主控因素，随着滑 坡宽度的增长，管道的极限荷载减小，危险点从滑坡中心移动至滑坡区外 1.1(L/2) 附近。

（5）发展横向滑坡管道管周土体参数智能识别方法。首先，利用滑坡管道 管土耦合模型，预先计算 9 种滑坡组合工况下、管道全生命周期内不同断面管体 应变模板数据集。然后，采用动态时间规整技术（DTW），对监测数据集与模板 数据集进行相似度智能匹配，将相似度最高的工况认定为滑坡现场管周土体物力 参数。算例表明，当布设多个监测断面，且各断面应变监测值随时间出现变化时， 管周参数辨识技术具有良好的辨识效果。最后，通过识别获得的物力参数对管道 正分析，提出横向滑坡作用下对埋地管道进行安全预警的分析流程。

The geographical environment along the long-distance oil and gas pipeline is complex, and it will inevitably pass through unfavorable geological areas such as mine goafs, collapsible loess areas, and mountain landslides. Safety accidents such as large-span pipeline suspension deformation and landslide-induced pipeline fractures occur from time to time, causing heavy casualties and economic losses. Carrying out stress analysis and risk assessment research on buried oil and gas pipelines in potential hazard areas of geological disasters has important theoretical and engineering significance for improving the level of disaster prevention and control of oil and gas pipeline networks and ensuring national public safety. 

This paper takes buried suspended pipelines and pipelines affected by lateral landslide as the research objects. Under the theoretical framework of elastoplastic foundation beams, the mechanical models of pipe-soil coupling of suspended pipelines and landslide pipelines are established respectively, and the calculation method of efficient pipeline model is developed. On the basis, this paper introduces dynamic time warping (DTW) technolique, and uses pipe strain monitoring data in order to intelligently identify the physical and mechanical parameters of soil around the pipe, to build a pipeline disaster safety evaluation system composed of the maximum stress zone, the remaining capacity of the pipeline and other indicators. The main research contents and results are as follows: 

(1) Establish a mechanical model of coupling action of pipe and soil for oil and gas pipelines. According to the lateral resistance response characteristics of the soil in different sections of the suspended pipeline, the pipeline is divided into three sections: suspended section, plastic resistance section and elastic resistance section. The paper establishes pipeline deflection control equation based on the theory of elastic-plastic foundation beams, and gives the definite solution conditions for the deflection and axial force of the buried suspended pipeline combining the boundary conditions and continuous conditions. According to the three working conditions of the lateral soil resistance of the pipeline under the increasing lateral landslide thrust(elastic resistance, plastic resistance and plastic area is smaller than landslide area, plastic resistance and plastic area is greater than landslide area), the landslide pipe deflection control equation is established based on the theory of elasto-plastic foundation beams, and combined with the boundary conditions and continuous conditions, the definite solution conditions for solving the deflection and axial force of the landslide are given. 

(2) Propose an efficient calculation method for solving the mechanical model of pipe-soil coupling action. According to the definite solution conditions of suspended pipelines and landslide pipelines, an explicit expression between the general solution of the deflection control equation and the pipeline axial force T and the plastic characterization length Δ is derived. A genetic algorithm is used to solve the nonlinear equations composed of T and Δ, so as to improve the accuracy and calculation efficiency of the pipe-soil coupling model. The analysis of the numerical examples shows that the semi-analytical and semi-numerical calculation results presented in this paper are in good agreement with the finite element numerical simulation, and can be conveniently used in engineering design and safety assessment.

(3) Carry out analysis of factors affecting soil parameters around buried suspended pipelines. Based on the mechanical model of the pipe-soil coupling action of the suspended pipeline, combined with the actual case, the effects of the linear rigidity of the soil, the vertical force of the overlying soil on the pipeline and the suspension span on the deflection curve, bending moment and maximum strain of the suspended pipeline are analyzed. The results show that the suspended span is the main controlling factor affecting the stress of the pipeline. When the suspended span L exceeds 100m, the soil outside the suspended segment will appear plastic, and the plastic zone will expand with the increase of the suspended span. If the elastic-plastic model is not used, the pipeline stress distribution will be overestimated. In addition, the maximum strain of the pipeline is constant at 1.02 (L/2) from the center of the suspension, and does not change with the change of the suspension span. It should be used as the key layout area of the pipe strain sensor. 

(4) Carry out an analysis of the factors affecting the soil parameters around the lateral landslide pipeline. Based on the mechanical model of the pipe-soil coupling action of the landslide pipeline, combined with the actual case, the dimensional curve q0/kD composed of the landslide thrust q0, the linear stiffness of the soil k and the outer diameter D of the pipeline, the width L of the landslide section on the deflection curve, bending moment and maximum strain of the landslide pipeline are analyzed. The results show that the width of the landslide section is the main controling factor affectings the stress of the pipeline. As the width of the landslide increases, the ultimate load of the pipeline decreases, and the dangerous point moves from the center of the landslide to 1.1 (L/2) outside the landslide area. 

(5) Develop intelligent identification methods of soil parameters around lateral landslide pipelines. First, using the pipe-soil coupling model of the landslide pipeline, the strain template data sets of the pipe sections with different cross sections in the Abstract V full life cycle of the pipeline under the nine kinds of landslide combination conditions are pre-calculated. Then, the dynamic time warping technique (DTW) is used to intelligently match the similarity between the monitoring data set and the template data set, and the working condition with the highest similarity is identified as the physical and mechanical parameter of the soil around the landslide site. The calculation example shows that when multiple monitoring sections are laid out and the strain monitoring value of each section changes with time, the parameter identification technique around the tube has a good identification effect. Finally, the pipeline is positively analyzed through the physical and mechanical parameters obtained by the identification, and the analysis process for the early safety warning of the buried pipeline under the effect of the lateral landslide is proposed.