基于人工合成透明土盾构隧道壁后同步注浆模型试验研究

发布时间：2018-03-28 08:01

本文选题：透明土　切入点：PIV技术　出处：《北京交通大学》2015年硕士论文

【摘要】：基于人工合成透明土能够直观观测土体内部变形的优势,将透明土作为盾构壁后注浆模型试验的模型土材料,借助PIV技术用激光器照射透明土层成像、CCD工业相机捕捉图像,并利用PIVview2C软件对图像进行信息提取分析,本文采用理论与物理模型试验相结合的研究方法开展盾构隧道壁后注浆模型试验,对盾构隧道壁后注浆控制地层沉降的效果及注浆浆液的填充情况和扩散范围进行了初步的探究性研究。本文主要工作内容和研究结论如下： 1)首先,综合分析了了人工合成透明土的理论基础、所用材料及组分、具体配制方法；然后,利用透明熔融石英砂作为颗粒材料和溶质溶于溶剂的方法配制溴化钙溶液为间隙流体材料合成了本模型试验中的透明土。透明土的透明效果随着熔融石英砂粒径的减小而变差,透明土放置过程中会出现干化现象。 2)对透明土进行了筛分试验、压缩试验、直剪试验、三轴试验等一系列常规土性实验,研究了透明土的基本物理力学性质,并与相应级配的标准砂进行了比较；各级配透明土与标准砂土摩擦角、压缩性具有相同的变化趋势,但黏聚力有差异,黏聚力三轴试验值较直剪试验结果偏大；各级配透明土的压缩性较相应级配标准砂土要小。总体而言,透明土材料能够较好的满足实际工程中土层变形模拟的要求。 3)对物理模型试验相似理论和PIV技术原理进行了简要介绍,依托上述理论研究并设计了盾构隧道壁后注浆模型试验系统,具体包括：试验箱主体、推进系统、注浆系统、激光器照射和CCD相机成像信息采集系统、PIVview2C软件信息提取和Origin软件后处理分析等分析系统。该试验的系统的研发为开展相关模型试验提供了技术可行的试验基础,并积累了相关经验供后续研究借鉴。 4)基于透明土先后开展了盾构法隧道未注浆段与注浆段对比试验、注浆压力对比试验,分析了透明土地层的沉降情况和注浆浆液的填充和扩散情况等。结果表明：注浆段地层沉降位移较未注浆段明显减小：提高注浆压力会减小地层的沉降,但过大的注浆压力会导致地层隆起;注浆压力越大浆液的填充性越好、扩散范围也越大；但是,在同种注浆压力下浆液的扩散范围基本不随隧道埋深的变化而改变。试验结果和结论可为盾构隧道壁后注浆地层变形控制和工艺改进等提供有益参考。
[Abstract]:Based on the advantage that synthetic transparent soil can directly observe the internal deformation of soil, the transparent soil is used as the model soil material for the model test of post-grouting model test of shield wall, and the image is captured by using PIV technology to illuminate the transparent soil layer with laser irradiation and CCD industrial camera to capture the image. Using PIVview2C software to extract and analyze the information of the image, this paper adopts the research method of combining theory with physical model test to carry out the model test of the rear grouting of shield tunnel wall. The effect of grouting behind shield tunnel wall on controlling stratum settlement and the filling condition and diffusion range of grouting slurry are studied preliminarily. The main contents and conclusions of this paper are as follows:. 1) first of all, the theoretical basis of synthetic transparent soil, the materials and components used, and the specific preparation methods are analyzed synthetically. The transparent soil in this model test was synthesized by using transparent fused quartz sand as granular material and solute solute solute in solvent to prepare calcium bromide solution as interstitial fluid material. The transparency effect of the transparent soil becomes worse with the decrease of the particle size of molten quartz sand. Drying will occur in the process of placing transparent soil. 2) screening test, compression test, direct shear test, triaxial test and so on were carried out to study the basic physical and mechanical properties of the transparent soil, and compared with the corresponding graded standard sand. The friction angle of transparent soil and standard sand has the same change trend, but the cohesive force is different, and the result of triaxial test of cohesion is larger than that of direct shear test. The compressibility of each grade of transparent soil is smaller than that of corresponding graded standard sand. Generally speaking, transparent soil materials can meet the requirements of soil deformation simulation in practical engineering. 3) the similarity theory of physical model test and the principle of PIV technology are briefly introduced. Based on the above theory, the model test system for rear grouting of shield tunnel wall is studied and designed, including: main body of test box, propulsion system, grouting system, etc. Laser irradiation and CCD camera imaging information acquisition system (PIVview2C software) and Origin software post-processing analysis system. The research and development of the system provides a technically feasible experimental basis for the development of related model tests. And has accumulated the correlation experience for the follow-up research to draw lessons from. 4) based on the transparent soil, the contrast test between the ungrouting section and the grouting section and the grouting pressure contrast test have been carried out successively in shield tunneling. The settlement of transparent soil layer and the filling and diffusion of grouting fluid are analyzed. The results show that the settlement displacement of grouting section is obviously reduced than that of non-grouting section, and the settlement of stratum will be reduced by increasing grouting pressure. However, too much grouting pressure can lead to formation uplift; the greater the grouting pressure, the better the filling capacity of the slurry, and the larger the diffusion range; however, Under the same grouting pressure, the diffusion range of the slurry does not change with the change of the tunnel depth. The experimental results and conclusions can provide a useful reference for the deformation control and technological improvement of the grouting formation behind the shield tunnel wall.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U455.43

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