本文選題：粘土　切入點(diǎn)：裂隙　出處：《哈爾濱工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：裂隙為污染物(或降雨)入滲和土體中水分的蒸發(fā)提供了重要的優(yōu)勢通道。裂隙與土體之間水量交換的定義為在滲透和蒸發(fā)條件下水在裂隙與土體之間的相互運(yùn)動(dòng),其包括滲透和蒸發(fā)兩種形式,滲透形式的水量交換是裂隙中優(yōu)勢流的重要形式,以水量交換率進(jìn)行數(shù)學(xué)描述。而目前的研究主要針對砂土中的圓柱形裂隙,對于粘土中平板裂隙與粘土間的水量交換率試驗(yàn)研究還處于空白。其主要的難點(diǎn)包括以下兩個(gè)方面:粘土中的裂隙寬度會(huì)隨著土體含水量的變化而開裂或者閉合;粘土中的裂隙寬度通常較小。對于蒸發(fā)形式的水量交換試驗(yàn)研究,目前研究得到的主要結(jié)論是裂隙的存在能夠顯著增加土體的蒸發(fā)量,但對于裂隙如何具體影響土體蒸發(fā)的研究還比較少。其主要困難是影響土體蒸發(fā)的因素眾多,即包括自然因素又包括土體自身因素,因此很難建立一個(gè)準(zhǔn)確計(jì)算單獨(dú)由裂隙產(chǎn)生的蒸發(fā)量的數(shù)學(xué)模型。本文針對粘土中裂隙的特點(diǎn)設(shè)計(jì)了一套試驗(yàn)裝置,通過含水量傳感器和張力計(jì)等測量系統(tǒng),定量地計(jì)算了粘土-裂隙間的水量交換率,并得到了粘土-裂隙間的界面滲透系數(shù)。同時(shí)研究了土體初始含水量和裂隙寬度對滲透形式試驗(yàn)水量交換率的影響。研究發(fā)現(xiàn)對于具有不同初始含水量的土體,其水量交換率在滲透初期最大,隨著土體中基質(zhì)吸力的降低而降低,粘土-裂隙間的界面滲透系數(shù)比土體的飽和滲透系數(shù)大一個(gè)數(shù)量級(jí)。不同裂隙寬度的土體,其水量交換率也是在滲透初期最大,隨著土體中基質(zhì)吸力的降低而降低。粘土與裂隙間的界面滲透系數(shù)也比土體的飽和滲透系數(shù)大一個(gè)數(shù)量級(jí)。當(dāng)土體中裂隙寬度不同時(shí),滲透初期不同裂隙寬度土體的水量交換率相差較大,隨著滲透的進(jìn)行,這種差別逐漸變小,最后水量交換率趨于穩(wěn)定。本文針對含裂隙土體蒸發(fā)的特點(diǎn)設(shè)計(jì)了一套試驗(yàn)裝置,通過含水量傳感器和張力計(jì)測量系統(tǒng),定量地研究了土體初始含水量和裂隙寬度對土體蒸發(fā)量和蒸發(fā)過程中裂隙周圍土體含水量變化的影響。研究發(fā)現(xiàn)對于不同裂隙寬度和不同初始含水量的土體,土體蒸發(fā)量在蒸發(fā)初期最大,隨著蒸發(fā)的進(jìn)行迅速降低,最后趨于穩(wěn)定。裂隙周圍土體的含水量在豎直方向隨著土體深度的增加而增加,在同一水平方向隨著距裂隙中心距離的增加而增加。土體中裂隙越大,土體的蒸發(fā)量也越大,土體初始含水量越接近土體最優(yōu)含水量,土體的蒸發(fā)量越大。
[Abstract]:Fissures provide important superior channels for pollutant (or rainfall) infiltration and evaporation of water in soil. Water exchange between fissure and soil is defined as the movement of water between fissure and soil under permeable and evaporation conditions. The water exchange is an important form of the dominant flow in a fissure, which is described mathematically by the water exchange rate, and the current research is mainly focused on the cylindrical fissure in sand. The experimental study on the water exchange rate between flat fissure and clay in clay is still blank. The main difficulties include the following two aspects: the crack width in clay will crack or close with the change of soil water content; The width of cracks in clay is usually small. For the experimental study of water exchange in the form of evaporation, the main conclusion of the present study is that the existence of cracks can significantly increase the evaporation of soil. However, there are few studies on how cracks affect soil evaporation. The main difficulty is that there are many factors that affect soil evaporation, that is, natural factors as well as soil itself. Therefore, it is difficult to establish a mathematical model to calculate the evaporation produced by cracks alone. In this paper, according to the characteristics of cracks in clay, a set of test equipment is designed, which is measured by water content sensor and tensometer, etc. The water exchange rate between clay and fracture is calculated quantitatively. At the same time, the influence of initial water content and crack width of soil on the water exchange rate of seepage test is studied. It is found that for soil with different initial water content, The water exchange rate of the soil decreases with the decrease of the soil matrix suction. The interfacial permeability coefficient between clay and fracture is one order of magnitude larger than the saturated permeability coefficient of soil. The water exchange rate is the highest in the early stage of infiltration and decreases with the decrease of the suction of the matrix. The interfacial permeability coefficient between clay and fracture is also one order of magnitude larger than the saturated permeability coefficient of soil. When the width of fracture in soil is different, The water exchange rate of soil with different fracture width is quite different in the early stage of permeability, and the difference becomes smaller gradually with the permeation, and the water exchange rate tends to be stable at the end. A set of experimental equipment is designed in this paper according to the characteristics of evaporation of fissured soil. Through the water content sensor and the tensometer measuring system, The effects of initial water content and crack width on soil evaporation and soil moisture content in the process of evaporation are quantitatively studied. The soil evaporation is the largest in the initial stage of evaporation, and decreases rapidly with the evaporation, and finally tends to stabilize. The water content of the soil around the fracture increases in the vertical direction with the increase of soil depth. In the same horizontal direction, with the increase of distance from the crack center, the larger the fissure, the larger the soil evaporation, the closer the soil initial water content is to the optimum soil water content, and the larger the soil evaporation is.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X141;TU41

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王鐵行;陳晶晶;李彥龍;;非飽和黃土地表蒸發(fā)的試驗(yàn)研究[J];干旱區(qū)研究;2014年06期

2 蔡武軍;凌道盛;徐澤龍;陳云敏;;單一裂隙優(yōu)勢滲流對黏土層防滲性能的影響分析[J];巖土力學(xué);2014年10期

3 李鳳霞;王學(xué)琴;郭永忠;許興;柯英;;寧夏引黃灌區(qū)鹽化土壤微生物區(qū)系及其指示意義[J];干旱區(qū)研究;2013年03期

4 翟聚云;魯潔;;非飽和膨脹土水分遷移的試驗(yàn)研究[J];土木建筑與環(huán)境工程;2010年02期

5 李王成;王為;馮紹元;陳紹軍;霍再林;;不同類型微型蒸發(fā)器測定土壤蒸發(fā)的田間試驗(yàn)研究[J];農(nóng)業(yè)工程學(xué)報(bào);2007年10期

6 唐朝生;施斌;劉春;王寶軍;;影響?zhàn)ば酝帘砻娓煽s裂縫結(jié)構(gòu)形態(tài)的因素及定量分析[J];水利學(xué)報(bào);2007年10期

7 孔令偉;陳建斌;郭愛國;趙艷林;呂海波;;大氣作用下膨脹土邊坡的現(xiàn)場響應(yīng)試驗(yàn)研究[J];巖土工程學(xué)報(bào);2007年07期

8 唐朝生;施斌;劉春;王寶軍;高瑋;;黏性土在不同溫度下干縮裂縫的發(fā)展規(guī)律及形態(tài)學(xué)定量分析[J];巖土工程學(xué)報(bào);2007年05期

9 陳建斌;孔令偉;趙艷林;呂海波;;非飽和土的蒸發(fā)效應(yīng)與影響因素分析[J];巖土力學(xué);2007年01期

10 謝云;李剛;陳正漢;張偉;魏學(xué)溫;劉述林;;復(fù)雜條件下膨脹土邊坡滲流和穩(wěn)定性分析[J];后勤工程學(xué)院學(xué)報(bào);2006年02期

相關(guān)碩士學(xué)位論文 前2條

1 張玉蓮;非飽和土滲透系數(shù)瞬態(tài)剖面測量方法及儀器的改進(jìn)[D];哈爾濱工業(yè)大學(xué);2011年

2 陳中奎;高量程張力計(jì)的研制及其應(yīng)用[D];哈爾濱工業(yè)大學(xué);2011年

，

本文編號(hào)：1574899