南水北调中线膨胀土渠道渗流稳定分析

发布时间：2018-01-15 17:10

本文关键词：南水北调中线膨胀土渠道渗流稳定分析　出处：《黑龙江大学》2014年硕士论文　论文类型：学位论文

【摘要】：南水北调中线工程总干渠中,部分渠段途经膨胀土地区,膨胀土是一种遇水膨胀、失水收缩的特殊性非饱和土。基于这一原因,需要对工程中的膨胀土渠段展开一系列的研究以确保整个工程的安全及工程实际意义的实现。本文针对南水北调中线工程中膨胀土渠段的渗流进行研究分析,确保渠道不会因渗流问题发生破坏。首先,要了解膨胀土的工程特性,明确膨胀上在工程中存在的一些问题;其次,结合渗流分析的基本理论和不同的渗流分析方法,开展室内试验和现场原型试验,并对室内实验和现场原型试验所测的数据进行整理分析;最后,结合试验测的的数据和分析结果应用专业渗流分析软件seep3D对渠道进行渗流分析。具体的内容包括：(])在初步了解膨胀土的特殊性质后,开展室内试验,进一步了解试验渠段膨胀土的物理力学性质,选取桩号K58++487.838处渠段的土体为研究对象,主要为Q1粘土夹壤土及粉细砂透镜体。通过试验得出：试验渠段主要成分Q1粘土的自由膨胀率较高,具有中等膨胀潜势,对渠道渗流会有较大影响。因此对Q1粘土进行重点室内实验,确定其物理力学性质。(2)为了使研究更加符合真实情况,得到更充分的依据,需要选取典型的膨胀土渠段进行现场原型试验。现场试验包含两方面内容：①对换填土和原状土进行水平位移监测,确定渠坡稳定性以及保证后续渗流分析具有实际意义；②对换填土和原状土的含水率和孔隙水压力进行监测,为后续软件模拟提供参考数据。(3)对试验渠段进行渗流分析。分析过程中,选用Seep3D软件对试验渠段进行渗流分析。Seep3D软件是专门的渗流分析软件,具备较完善的理论基础,模拟呈现三维效果,更加符合工程的实际情况,因此被广泛应用于实际工程的渗流研究。在应用软件进行模拟的过程中,首先设定试验渠道渗流分析的范围和边界条件,确定渗流分析模型；然后确定三种计算工况,分别为设计水位、检修期和检修期加降雨情况；最后通过软件中提供的分析方法,对三种工况分别进行渗流分析。通过分析可知,在严格控制施工质量的情况下,对渠道范围内的膨胀土采取开挖换填、压实并加盖复合土工膜和混凝土板等措施可以确保渠道不会发生渗流破坏。
[Abstract]:In the main canal of the middle route project of South-to-North Water transfer Project, some of the channels pass through the expansive soil area. The expansive soil is a special unsaturated soil with water expansion and water loss shrinkage. In order to ensure the safety of the whole project and realize the practical significance of the project, a series of research on the expansive soil channel section in the project needs to be carried out. In this paper, the seepage flow of the expansive soil channel section in the middle route of South-to-North Water transfer Project is studied and analyzed. First of all, it is necessary to understand the engineering characteristics of expansive soil and make clear some problems existing in the project. Secondly, combined with the basic theory of seepage analysis and different seepage analysis methods, the laboratory test and field prototype test are carried out, and the data measured in indoor experiment and field prototype test are collated and analyzed. Finally, combined with the experimental data and analysis results, the seepage analysis of the channel is carried out with the professional seepage analysis software seep3D. The specific contents include: (1) after the preliminary understanding of the special properties of expansive soil. In order to further understand the physical and mechanical properties of expansive soil in the section of the test canal, the soil mass at the section of pile number K58 487.838 is selected as the research object. It is mainly Q1 clay clay-loam soil and silty sand lens. The test results show that the free expansion ratio of Q1 clay is high, and it has medium expansion potential. Therefore, the key laboratory experiments on Q1 clay are carried out to determine its physical and mechanical properties. (2) in order to make the research more consistent with the real situation, a more adequate basis is obtained. It is necessary to select typical expansive soil section to carry on the field prototype test. The field test includes two aspects: 1 to monitor the horizontal displacement of the replacement fill and the undisturbed soil. It is of practical significance to determine the stability of channel slope and ensure the subsequent seepage analysis. (2) monitoring the moisture content and pore water pressure of the replacement fill and undisturbed soil, and providing reference data for the subsequent software simulation. Seep3D software is a special seepage analysis software, which has perfect theoretical foundation and presents 3D effect. It is more in line with the actual situation of the project, so it is widely used in the seepage research of practical engineering. In the process of simulation, the scope and boundary conditions of the seepage analysis of the test channel are first set. Determine the seepage analysis model; Then three kinds of calculation conditions are determined, which are design water level, maintenance period and repair period plus rainfall. Finally, through the analysis method provided in the software, the seepage analysis of three working conditions is carried out respectively. Through the analysis, we can know that under the condition of strictly controlling the construction quality, the expansive soil in the canal scope should be excavated and filled. Compaction and capping of composite geomembrane and concrete slabs can ensure that seepage failure will not occur in the channel.
【学位授予单位】：黑龙江大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV672;TU443

【共引文献】