發(fā)布時(shí)間：2018-05-11 09:17

  本文選題：多孔介質(zhì) + 顆粒��； 參考：《北京交通大學(xué)》2013年博士論文

【摘要】：飽和多孔介質(zhì)中顆粒遷移特性的研究在地下污染物擴(kuò)散、核廢料處置、石油開(kāi)采、地下水回灌和水工結(jié)構(gòu)的內(nèi)部侵蝕破壞等方面有很重要的研究意義。本文通過(guò)對(duì)經(jīng)典的一維顆粒過(guò)濾模型進(jìn)行修正,求得了不同的注入方式以及含有源匯項(xiàng)的解析解。其次,建立了考慮彌散作用和沉積顆粒再釋放作用影響的顆粒遷移的三維模型,將顆粒遷移問(wèn)題的研究從一維向三維空間進(jìn)行拓展。求得的解析解可以預(yù)測(cè)多孔介質(zhì)中顆粒濃度、驗(yàn)證更加復(fù)雜的數(shù)值模型以及確定試驗(yàn)參數(shù)等。另一方面,通過(guò)室內(nèi)土柱試驗(yàn)研究了滲流速度、滲流方向、顆粒濃度以及顆粒粒徑分布等對(duì)顆粒遷移和沉積特性的影響。其次,探究了滲流速度增量和顆粒粒徑對(duì)沉積顆粒再釋放特性的影響。主要的研究?jī)?nèi)容包括： (1)將多孔介質(zhì)視為飽和、均質(zhì)和各向同性介質(zhì),通過(guò)在顆粒沉積動(dòng)力方程中考慮彌散作用,建立了飽和多孔介質(zhì)中顆粒遷移的一維模型,求得了三種不同的顆粒注入方式(短時(shí)注入、瞬時(shí)注入以及注入濃度衰減)和含有源匯項(xiàng)時(shí)的相應(yīng)的解析解,并且對(duì)解析解中各種遷移參數(shù)進(jìn)行了討論。對(duì)不同情況的解析解的分析可知,隨著時(shí)間、沉積系數(shù)、遷移距離或者線源寬度等參數(shù)中任意參數(shù)的增大,顆粒的濃度峰值逐漸減小。沉積動(dòng)力方程中忽略彌散作用會(huì)對(duì)顆粒濃度有很大的影響,不同的情況下的影響規(guī)律大不相同。 (2)以求得的一維解析解為基礎(chǔ),建立三維空間的顆粒遷移模型,模型分別在沉積動(dòng)力方程中考慮彌散作用和沉積顆粒再釋放作用的影響,并通過(guò)Laplace變換和Fourier變換求得了相應(yīng)解析解的通解形式。其次,利用推導(dǎo)出的解析解的通解形式求出了點(diǎn)源和面源形式下的瞬時(shí)注入和周期性注入的具體形式的解析解。最后,以點(diǎn)源瞬時(shí)注入情況下的解析解為例,對(duì)各種遷移參數(shù)進(jìn)行了詳細(xì)的討論。對(duì)于考慮彌散作用的三維遷移模型的解析解來(lái)說(shuō),隨著時(shí)間的增大,低濃度等高線的范圍逐漸向四周擴(kuò)大,高濃度等高線的范圍逐漸縮小。隨著沉積系數(shù)的增大,濃度等高線的范圍逐漸縮小。對(duì)于考慮顆粒釋放作用的三維遷移模型來(lái)說(shuō),釋放系數(shù)越大,相應(yīng)的濃度等高線的范圍越大。 (3)通過(guò)土柱試驗(yàn)研究顆粒粒徑、顆粒濃度和水動(dòng)力對(duì)顆粒遷移和沉積特性的影響,開(kāi)展了4種不同粒徑和4種不同濃度的試驗(yàn)系列,每個(gè)系列中進(jìn)行了3種不同的滲流速度的試驗(yàn)。結(jié)果表明：對(duì)于大小和形狀一定的顆粒來(lái)說(shuō),通過(guò)測(cè)試顆粒濁度來(lái)反映其濃度的變化能取得較好的結(jié)果。其次,對(duì)于同一粒徑的顆粒,滲流速度越大,流出液中顆粒的濃度峰值越大。在同一滲流速度條件下,顆粒粒徑越大,流出液中其濃度峰值越小。另外,滲流速度一定時(shí),顆粒的濃度存在一個(gè)和滲流速度相關(guān)的臨界值,顆粒的臨界濃度隨著滲流速度增加也逐漸增大。 (4)通過(guò)試驗(yàn)的手段研究粒徑和滲流速度對(duì)多孔介質(zhì)中顆粒釋放特性的影響。根據(jù)滲流速度增量的不同,試驗(yàn)分為兩種不同的試驗(yàn)系列,在每一個(gè)試驗(yàn)系列中分別對(duì)兩種不同粒徑的顆粒進(jìn)行試驗(yàn)。其次,研究了滲流速度增量和顆粒粒徑對(duì)沉積顆粒釋放規(guī)律的影響。最后,對(duì)試驗(yàn)完成后石英砂中沉積顆粒量隨深度變化的特性進(jìn)行了定量分析。一般來(lái)說(shuō),中位粒徑小的顆粒的釋放量要大于相應(yīng)的中位粒徑較大的顆粒。滲流速度的增量不同,沉積的顆粒的特征也大不相同。 (5)利用室內(nèi)土柱試驗(yàn)探究了滲流速度、滲流方向以及顆粒分布對(duì)飽和多孔介質(zhì)中顆粒遷移和沉積特性的影響機(jī)制。試驗(yàn)包括三種不同的滲流方向的試驗(yàn)系列(向下流,水平流和向上流)。同時(shí),以修正后的對(duì)流彌散方程求得的解析解對(duì)試驗(yàn)曲線進(jìn)行擬合,對(duì)3種不同粒徑分布的顆粒的遷移參數(shù)進(jìn)行對(duì)比分析,揭示了不同水力條件下顆粒的粒徑分布對(duì)其遷移和沉積特性的影響機(jī)制。顆粒的彌散度和滲流方向有很大的關(guān)系,在滲流自上至下時(shí)彌散度的變化最明顯。另外,隨著滲流速度的增加,顆粒的沉積系數(shù)隨之減小,相應(yīng)的回收率隨之增加,并且中位粒徑或均一性指數(shù)對(duì)顆粒的沉積特性有一定的影響。
[Abstract]:The study of particle migration in saturated porous media has important research significance in the aspects of underground pollutant diffusion, nuclear waste disposal, petroleum exploitation, groundwater recharge and the internal erosion and destruction of the hydraulic structure. This paper has corrected the classic one-dimensional particle filtration model and obtained different injection modes and source and sink. Secondly, the three-dimensional model of particle migration, which considers the effect of diffusion and sediment release, is established, and the study of particle migration is extended from one dimension to three dimensional space. The analytical solution can predict the particle concentration in porous media, verify the more complex numerical model and determine the test parameters. On the other hand, the influence of percolation velocity, percolation direction, particle concentration and particle size distribution on the migration and deposition characteristics of particles is studied through the laboratory soil column test. Secondly, the influence of the increment of flow rate and particle size on the re release characteristics of the deposited particles is investigated.
(1) the porous medium is considered as saturated, homogeneous and isotropic medium. By considering dispersion in the dynamic equation of particle deposition, a one-dimensional model of particle migration in saturated porous media is established, and three different injection modes (short time injection, instantaneous injection and injection concentration attenuation) and corresponding source and sink terms are obtained. The analytical solution of the analytical solution is discussed and the analytical solutions of the analytical solutions show that the peak concentration of the particles gradually decreases with the increase of any parameters in the parameters such as time, sedimentation coefficient, migration distance or line source width. The influence rule is quite different under different circumstances.
(2) on the basis of one dimensional analytical solution, the model of particle migration in three-dimensional space is established. The effects of dispersion and sediment release are considered in the kinetic equation respectively. The general solution form of the corresponding analytical solution is obtained by Laplace transformation and Fourier transformation. Secondly, the general solution of the analytical solution is obtained. The analytical solutions of instantaneous injection and periodic injection in the form of point source and surface source are obtained. Finally, with the analytical solution of the instantaneous injection of point source as an example, the various migration parameters are discussed in detail. For the solution analysis of the three-dimensional migration model considering the dispersion effect, with the increase of time, low concentration and so on The range of high line is gradually expanded to four sides, and the range of high concentration contour is gradually reduced. As the deposition coefficient increases, the range of the concentration contour is gradually reduced. For the three-dimensional migration model considering the release of particles, the greater the release coefficient, the greater the range of the corresponding concentration contour.
(3) through the soil column test, the effects of particle size, particle concentration and hydrodynamic force on the particle migration and deposition characteristics were studied. 4 different particle sizes and 4 different concentrations were carried out. 3 different percolation velocities were tested in each series. The results showed that the particles were tested by the particles for the size and shape of the particles. The higher the velocity of the percolation, the greater the peak concentration of the particles in the effluent. The greater the particle size, the smaller the peak concentration in the effluent at the same percolation velocity. In addition, the concentration of the particles is one and the other when the seepage velocity is certain. The critical value of flow velocity also increases with the increase of seepage velocity.
(4) the effect of particle size and percolation velocity on the release characteristics of particles in porous media is studied by means of experimental methods. According to the difference of the increment of seepage velocity, the experiment is divided into two different test series. In each test series, the particles of two different particle sizes are tested. Secondly, the increment of the seepage velocity and the particle size are studied. In the end, the quantitative analysis of the characteristics of the sediment particles in the quartz sand with depth changes after the test is completed. In general, the release of the particles with small medium size is larger than that of the corresponding particles with larger medium size. The increment of the velocity of the seepage is different, and the characteristics of the deposited particles are very different.
(5) the influence mechanism of percolation velocity, seepage direction and particle distribution on the particle migration and deposition in saturated porous media is investigated by the laboratory soil column test. The test series including three different seepage directions (downward flow, horizontal flow and upward flow). At the same time, the analytical solution obtained by the modified convection diffusion equation is tested. The test curves are fitted and the migration parameters of 3 particles with different particle sizes are compared and analyzed. The influence mechanism of particle size distribution on the migration and deposition characteristics under different hydraulic conditions is revealed. The dispersion degree of particles is closely related to the direction of seepage, and the variation of the dispersion is most obvious when the seepage is from the upper to the bottom. In addition, the particle size distribution is the most obvious. With the increase of the seepage velocity, the deposition coefficient of the particles decreases and the corresponding recovery rate increases, and the grain size or homogenization index has a certain influence on the deposition characteristics of the particles.

【學(xué)位授予單位】：北京交通大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2013
【分類號(hào)】：TU46

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 孫尚業(yè);蔣美蓉;王波;金豐年;;九華山隧道穿越段明城墻沉降的三維數(shù)值分析[J];解放軍理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年01期

2 王德民,程杰成,吳軍政,王剛;聚合物驅(qū)油技術(shù)在大慶油田的應(yīng)用[J];石油學(xué)報(bào);2005年01期

3 王正茂;廖廣志;;中國(guó)陸上油田聚合物驅(qū)油技術(shù)適應(yīng)性評(píng)價(jià)方法研究[J];石油學(xué)報(bào);2007年03期

4 帖卉霞;;淺埋近距隧道下穿高速公路差異沉降率理論分析與施工措施[J];鐵道標(biāo)準(zhǔn)設(shè)計(jì);2008年04期

5 洪開(kāi)榮;盾構(gòu)隧道穿越廣州火車站站場(chǎng)的設(shè)計(jì)與施工[J];現(xiàn)代隧道技術(shù);2002年06期

6 馬立軍,閆建華,李志勇;聚合物驅(qū)油技術(shù)在大港油田港西三區(qū)的推廣應(yīng)用[J];油氣地質(zhì)與采收率;2001年06期

7 姚海波;王夢(mèng)恕;張頂立;孔恒;;熱力隧道下穿地面建筑物的安全評(píng)價(jià)與對(duì)策[J];巖土力學(xué);2006年01期

8 逄鐵錚;;全程注漿在隧道穿越既有建筑物中的試驗(yàn)研究[J];巖土力學(xué);2008年12期

9 呂培林;周順華;;軟土地區(qū)盾構(gòu)隧道下穿鐵路干線引起的線路沉降規(guī)律分析[J];中國(guó)鐵道科學(xué);2007年02期

10 張成平;張頂立;吳介普;駱建軍;;暗挖地鐵車站下穿既有地鐵隧道施工控制[J];中國(guó)鐵道科學(xué);2009年01期

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