【摘要】：隨著理論研究的深入以及過(guò)程實(shí)踐的發(fā)展,非飽和滲流問(wèn)題在巖土工程與環(huán)境巖土工程中受到了越來(lái)越多的重視,而非飽和滲透系數(shù)是非飽和滲流分析的必要環(huán)節(jié)。目前,非飽和滲透系數(shù)已在測(cè)試方法、模型建立和影響因素等方面得到了深入研究。但是,密實(shí)程度與水力路徑對(duì)非飽和滲透系數(shù)的影響規(guī)律與機(jī)制尚不明確。本文以荊門(mén)弱膨脹土為研究對(duì)象,采用室內(nèi)試驗(yàn)、理論分析與數(shù)值模擬的方法研究密實(shí)程度與水力路徑對(duì)壓實(shí)膨脹土非飽和滲透系數(shù)的影響規(guī)律,在此基礎(chǔ)上,模擬降雨入滲與蒸發(fā)行為,主要研究?jī)?nèi)容與成果如下:(1)通過(guò)變水頭滲透試驗(yàn),獲得了孔隙比在工程尺度范圍內(nèi)的荊門(mén)弱膨脹土飽和滲透系數(shù)的變動(dòng)規(guī)律,在此基礎(chǔ)上,選用指數(shù)函數(shù)描述飽和滲透系數(shù)與孔隙比的關(guān)系,取得了較好的擬合效果。(2)采用TRIM方法,測(cè)得6種不同密實(shí)程度下荊門(mén)弱膨脹土的瞬態(tài)排水量與時(shí)間的函數(shù)關(guān)系,并以此函數(shù)關(guān)系作為目標(biāo)函數(shù),根據(jù)試驗(yàn)的初始、邊界條件,結(jié)合數(shù)值模擬方法求解Richards方程。通過(guò)Hydrus-1D反演模擬,獲得6種密實(shí)程度試樣脫吸濕路徑下的土水特征曲線、非飽和滲透系數(shù)函數(shù)和吸應(yīng)力曲線。(3)結(jié)果表明:隨著密實(shí)程度增大,試樣的進(jìn)氣值增大,持水能力增強(qiáng),非飽和滲透系數(shù)減小,吸應(yīng)力變化越范圍增大。不同水力路徑下,土水特征曲線、吸應(yīng)力曲線以及相對(duì)滲透系數(shù)曲線,呈現(xiàn)出明顯的水力滯回效應(yīng)。非飽和滲透函數(shù)用體積含水率表達(dá)時(shí),滯回效應(yīng)并不顯著,但是當(dāng)用吸力表達(dá)非飽和滲透函數(shù)時(shí),體現(xiàn)出較明顯的滯回效應(yīng)。(4)基于反演結(jié)果,分析密實(shí)程度與水力路徑對(duì)VG模型參數(shù)α、n的影響,構(gòu)建了VG模型參數(shù)α、n與土體密度、水力路徑相關(guān)關(guān)系的數(shù)學(xué)描述。(5)在Hydrus-1D程序中,采用不同密實(shí)程度與水力路徑下試樣的VG模型參數(shù),模擬降雨入滲與蒸發(fā)行為。明確了密實(shí)程度與水力路徑對(duì)降雨入滲與蒸發(fā)過(guò)程的影響規(guī)律。
[Abstract]:With the development of theoretical research and process practice, unsaturated seepage problem has been paid more and more attention in geotechnical engineering and environmental geotechnical engineering, and unsaturated permeability coefficient is a necessary link in unsaturated seepage analysis. At present, unsaturated permeability coefficient has been deeply studied in testing methods, modeling and influencing factors. However, the influence of density and hydraulic path on unsaturated permeability is unclear. In this paper, the influence of density and hydraulic path on unsaturated permeability coefficient of compacted expansive soil is studied by laboratory test, theoretical analysis and numerical simulation, taking Jingmen weakly expansive soil as the research object, and on the basis of which, the influence of density degree and hydraulic path on unsaturated permeability coefficient of compacted expansive soil is studied. The main research contents and results of simulating rainfall infiltration and evaporation behavior are as follows: (1) the variation of saturated permeability coefficient of Jingmen weakly expansive soil with void ratio in engineering scale is obtained through the permeability test with variable head. The exponential function is used to describe the relationship between saturation permeability coefficient and porosity ratio. (2) by using TRIM method, the function relationship between transient displacement and time of Jingmen weakly expansive soil is obtained by using TRIM method. According to the initial and boundary conditions of the experiment and the numerical simulation method, the Richards equation is solved by using the function relation as the objective function. Through Hydrus-1D inversion simulation, the soil-water characteristic curve, unsaturated permeability coefficient function and absorption stress curve under desorption path of 6 kinds of dense degree samples are obtained. (3) the results show that the inlet air value of the sample increases with the increase of compaction degree. With the increase of water holding capacity, the unsaturated permeability coefficient decreases, and the variation of absorption stress increases. Under different hydraulic paths, the characteristic curve of soil and water, the curve of absorbing stress and the curve of relative permeability coefficient show obvious hydraulic hysteretic effect. The hysteretic effect is not significant when the unsaturated permeation function is expressed by volume water content, but the hysteretic effect is obvious when the unsaturated permeation function is expressed by suction. (4) based on the inversion results, Based on the analysis of the influence of density degree and hydraulic path on the parameter 偽 n of VG model, a mathematical description of the correlation between the parameter 偽 n of VG model and soil mass density and hydraulic path is established. (5) in Hydrus-1D program, The VG model parameters of samples with different compactness and hydraulic path were used to simulate rainfall infiltration and evaporation behavior. The influence of density degree and hydraulic path on rainfall infiltration and evaporation process is clarified.
【學(xué)位授予單位】：信陽(yáng)師范學(xué)院
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TU443

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張昊;顧強(qiáng)康;張仁義;;Mualem模型中的飽和導(dǎo)水率修正研究[J];水土保持通報(bào);2015年03期

2 蔡國(guó)慶;盛岱超;周安楠;;考慮初始孔隙比影響的非飽和土相對(duì)滲透系數(shù)方程[J];巖土工程學(xué)報(bào);2014年05期

3 胡冉;陳益峰;周創(chuàng)兵;;考慮變形效應(yīng)的非飽和土相對(duì)滲透系數(shù)模型[J];巖石力學(xué)與工程學(xué)報(bào);2013年06期

4 周葆春;張彥鈞;馮冬冬;湯致松;馬全國(guó);;荊門(mén)非飽和壓實(shí)膨脹土的吸力特征及其本構(gòu)方程[J];巖石力學(xué)與工程學(xué)報(bào);2013年02期

5 周葆春;孔令偉;;考慮體積變化的非飽和膨脹土土水特征[J];水利學(xué)報(bào);2011年10期

6 周葆春;孔令偉;郭愛(ài)國(guó);;荊門(mén)弱膨脹土的脹縮與滲透特性試驗(yàn)研究[J];巖土力學(xué);2011年S2期

7 吳禮舟;黃潤(rùn)秋;;非飽和土滲流及其參數(shù)影響的數(shù)值分析[J];水文地質(zhì)工程地質(zhì);2011年01期

8 孔令偉;周葆春;白顥;陳偉;;荊門(mén)非飽和膨脹土的變形與強(qiáng)度特性試驗(yàn)研究[J];巖土力學(xué);2010年10期

9 陳輝;韋昌富;陳盼;伊盼盼;顏榮濤;;一種測(cè)定非飽和土-水力學(xué)參數(shù)的方法[J];巖土力學(xué);2010年10期

10 張雪東;趙成剛;劉艷;;變形對(duì)非飽和土滲透系數(shù)影響規(guī)律模擬研究[J];工程地質(zhì)學(xué)報(bào);2010年01期

相關(guān)會(huì)議論文 前1條

1 趙敏;謝定義;劉奉銀;;非飽和土滲水系數(shù)實(shí)驗(yàn)測(cè)定的新方法[A];中國(guó)土木工程學(xué)會(huì)第八屆土力學(xué)及巖土工程學(xué)術(shù)會(huì)議論文集[C];1999年

相關(guān)碩士學(xué)位論文 前3條

1 冉冬琴;干濕條件下壓實(shí)粘土滲透系數(shù)的預(yù)測(cè)研究[D];武漢理工大學(xué);2013年

2 周冬;應(yīng)力作用下非飽和土土水特征曲線及滲透性研究[D];西安理工大學(xué);2010年

3 王曉峰;降雨入滲對(duì)非飽和土邊坡穩(wěn)定性影響的研究[D];西安建筑科技大學(xué);2003年

，

本文編號(hào)：2147997