土与混凝土接触渗流破坏试验及数值模拟研究

发布时间：2018-06-23 22:56

本文选题：土石坝 + 接触渗流　；参考：《山东大学》2017年硕士论文

【摘要】：土石坝因结构形式简单、适用范围广、造价低等特点在国内外水利工程中广泛应用。土石坝中的混凝土输水管涵是一种应用广泛的水工建筑物。在实际工程中,土石坝的渗流问题已成为坝工建设中一项非常重要的课题,特别是由于库水位的提高,库水会通过坝体与混凝土涵管接触面向下游渗透,一旦发生渗流破坏,会对工程造成严重的损失。在实际土石坝监测中,由于土石坝与混凝土管涵接触处的压实度不够、没有反滤层工程防护措施等,较多坝体与管涵接触面的地方出现了渗流破坏现象,对坝体安全运营产生很大影响。因此,研究土与混凝土接触渗流破坏机理及影响因素,对保证工程安全具有重要意义。土石坝与混凝土输水管涵的接触渗流问题属于典型的土与混凝土接触渗流问题。本文通过室内试验和数值模拟相结合的方法,研究土与混凝土接触渗流的影响因素,总结研究该现象发生的原因、启动条件和破坏条件。并该研究内容应用于大屯水库工程实际,分析管涵周围土体渗透系数变化对接触渗流破坏的影响,为土坝安全运营提供了科学依据。论文总结了土与混凝土接触渗流的国内外研究现状,确定了影响土与混凝土接触渗流的三个主要影响因素:土体压实度、含粘量、反滤层;设计不同的试验工况开展室内试验,研究了控制接触渗流破坏的三个影响因素与启动水力坡降、破坏水力坡降的变化关系:土样压实度越高、含粘量越大、设置反滤层均可提高启动水力坡降和破坏坡降;通过ABAQUS数值分析不同工况启动水力坡降、破坏坡降的变化情况,并与试验结果进行对照;由于工程实际中水力坡降的变化与土体渗透系数的变化密不可分,将以上方法应用于大屯水库大坝工程实际中,通过渗透系数的变化模拟不同施工压实度,总结坝体与混凝土管涵接触渗流流速变化,为理论研究与实际工程安全运营提供科学合理的参考依据。
[Abstract]:Earth-rock dam is widely used in water conservancy projects at home and abroad because of its simple structure, wide application range and low cost. Concrete aqueduct culvert in earth-rock dam is a widely used hydraulic structure. In practical engineering, the seepage problem of earth-rock dam has become a very important subject in dam construction, especially because of the increase of reservoir water level, the reservoir water will infiltrate downstream through the interface between dam body and concrete culvert pipe, once seepage failure occurs, It will cause serious damage to the project. In the actual monitoring of earth-rock dam, because of the insufficient compaction of the contact between earth-rock dam and concrete pipe culvert, and the absence of protective measures of filter layer engineering, the seepage failure occurs in more places where the interface between dam body and concrete pipe culvert appears. It has great influence on the safe operation of dam body. Therefore, it is of great significance to study the failure mechanism and influencing factors of contact seepage between soil and concrete to ensure engineering safety. The contact seepage between earth-rock dam and concrete pipe culvert is a typical contact seepage problem between soil and concrete. In this paper, the influence factors of contact seepage between soil and concrete are studied by means of laboratory test and numerical simulation, and the causes, starting conditions and failure conditions of the phenomenon are summarized and studied. The research content is applied to the engineering practice of Datun Reservoir, and the influence of the change of soil permeability coefficient around the pipe culvert on the contact seepage failure is analyzed, which provides a scientific basis for the safe operation of the earth dam. This paper summarizes the research status of contact seepage between soil and concrete at home and abroad, and determines three main factors that affect the contact seepage between soil and concrete: soil compaction, viscosity content, filter layer, design of different test conditions to carry out laboratory tests. The relationship between three influencing factors of controlling contact seepage failure and start-up hydraulic gradient and the change of damage hydraulic gradient is studied: the higher the compaction degree of soil sample, the greater the viscosity content, and the setting of filter layer can increase the starting hydraulic gradient and damage slope; Through Abaqus numerical analysis of the change of hydraulic slope and damage slope under different working conditions, and compared with the test results, because the change of hydraulic slope in engineering practice is closely related to the change of soil permeability coefficient, The above method is applied to the dam engineering of Datun Reservoir. Through the variation of permeability coefficient to simulate different compaction degree of construction, the change of flow velocity of contact seepage between dam body and concrete pipe culvert is summarized. It provides a scientific and reasonable reference for theoretical research and practical engineering safety operation.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV223.4

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