车行道下方埋地管道的力学性状研究

发布时间：2018-04-19 02:10

本文选题：埋地管道 + 交通荷载　；参考：《重庆大学》2016年硕士论文

【摘要】：随着经济的高速发展和城镇化进程的推进,埋地管道在当前社会中的应用已非常广泛。作为物料运输的一种有效手段,埋地管道广泛应用于市政、水利、运输和能源等领域,在现代工农业和人民生活中起着重要的作用。随之而来的是管道种类愈加多样化,管材越来越丰富,管道所承受的荷载也越来越复杂。车行道下方的埋地管道受覆土荷载及路面交通荷载的作用,容易产生变形失稳、破裂或渗漏等事故。一旦发生破坏事故,检查和维修都比较困难,会给居民生活带来较大影响并造成资源浪费。本文以高密度聚乙烯管为研究对象,在总结埋地管道力学分析、交通荷载模拟、管道结构计算和路基路面工程等课题研究现状的基础上,采用理论分析、算例对比验证、数值模拟等方法,分析管道土压力、管道横截面变形和管土相互作用理论,分别建立二维和三维模型,对土体自重作用、静荷载作用和车辆荷载作用下埋地管道的力学性状和变形特性进行一系列研究。研究内容和主要结论有:(1)车行道下埋地管道系统包括管道、土体和交通荷载三大部分,围绕这三个部分,探讨现有埋地管道土压力计算理论、管道截面径向变形分析理论以及地面附加车辆荷载计算方法,结合算例将现有经典计算理论与有限元分析进行验证、对比,分析理论计算的不足之处及误差情况。(2)建立二维有限元模型,研究埋地管道的横截面力学性状和变形特性,分析管道埋深、管径、管土相对模量、荷载作用位置和大小等因素对管道受力特性和变形的影响。埋地管道竖向变形和最大Mises应力与管顶竖向土压力成正比,随埋深增加覆土压力增加,路面荷载附加压力减小,理论上存在一个最佳埋深;埋深相同的情况下,小口径管更容易发生破坏,刚性管比柔性管更容易破坏。(3)将道路结构、埋地管道和路面交通荷载作为一个相互作用的有机整体,建立管道路基系统三维模型,分析三维模型管道在荷载作用下,管道截面变形和内力分布规律,研究埋地管道在不同交通荷载作用下的力学性状,讨论了管道埋深、车辆荷载种类、荷载作用位置和车速等因素对管道受力及变形的影响。埋地管线危险点与管道两端约束条件有关;不同交通荷载作用下,管道力学响应表现出不同特点,车速和轮压对管道力学响应和变形均有影响。本文研究的方法和成果,可为实际工程埋地管道的设计与施工提供一定的理论依据,为进一步相关研究提供参考。
[Abstract]:With the rapid development of economy and the advancement of urbanization, buried pipelines have been widely used in the current society.As an effective means of material transportation, buried pipeline is widely used in the fields of municipal, water conservancy, transportation and energy, and plays an important role in modern industry, agriculture and people's life.Then the variety of pipeline is becoming more and more diversified, the pipe material is more and more abundant, and the load of pipeline is becoming more and more complex.The buried pipeline under the vehicular road is liable to deformation, instability, rupture or leakage due to the action of overlying earth load and road traffic load.Once damage accident occurs, inspection and maintenance are difficult, which will have a great impact on residents' lives and lead to waste of resources.In this paper, high-density polyethylene pipe is taken as the research object. On the basis of summarizing the current research situation of buried pipeline mechanics analysis, traffic load simulation, pipeline structure calculation and subgrade and pavement engineering, theoretical analysis is adopted, and numerical examples are compared and verified.Numerical simulation and other methods are used to analyze the theories of pipeline earth pressure, pipeline cross-section deformation and pipe-soil interaction, and to establish two-dimensional and three-dimensional models, respectively.The mechanical properties and deformation characteristics of buried pipeline under static load and vehicle load are studied.The research contents and main conclusions are as follows: (1) the buried pipeline system under the vehicular road includes three parts: pipeline, soil and traffic load. Around these three parts, the existing theory of calculating the earth pressure of buried pipeline is discussed.The radial deformation analysis theory of pipeline section and the calculation method of additional vehicle load on the ground are compared with the existing classical calculation theory and finite element analysis.(2) A two-dimensional finite element model is established to study the cross section mechanical properties and deformation characteristics of buried pipeline, and to analyze the buried depth, diameter and relative modulus of pipe soil.The influence of load position and size on the stress characteristics and deformation of pipeline.The vertical deformation and maximum Mises stress of buried pipeline are directly proportional to the vertical earth pressure at the top of the pipe. With the increase of buried depth, the additional pressure of pavement load decreases.The rigid pipe is easier to destroy than the flexible pipe. The road structure, buried pipeline and road surface traffic load are taken as an organic whole, and the three-dimensional model of pipeline subgrade system is established.This paper analyzes the distribution law of cross-section deformation and internal force of 3D model pipeline under load, studies the mechanical properties of buried pipeline under different traffic loads, discusses the buried depth of pipeline and the type of vehicle load.The influence of load position and speed on the stress and deformation of pipeline.The dangerous point of buried pipeline is related to the constraint conditions at both ends of pipeline, the mechanical response of pipeline shows different characteristics under different traffic loads, and the speed and wheel pressure have influence on the mechanical response and deformation of pipeline.The methods and results of this paper can provide some theoretical basis for the design and construction of buried pipeline in practical engineering and provide reference for further related research.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU990.3

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