【摘要】：非飽和土與飽和土的根本差異在于非飽和土中的孔隙水壓力為負(fù)值�？紫稓鈮号c負(fù)孔隙水壓力的差值定義為基質(zhì)吸力,用來(lái)體現(xiàn)非飽和土的應(yīng)力特征。將基質(zhì)吸力與土含水率的關(guān)系曲線稱(chēng)為土-水特征曲線(Soil-Water Characteristic Curve),簡(jiǎn)稱(chēng)SWCC。SWCC是非飽和土的一個(gè)重要本構(gòu)關(guān)系,可以用來(lái)分析和預(yù)測(cè)土的變形、強(qiáng)度和滲透性,因此SWCC是非飽和土研究的基礎(chǔ)�；|(zhì)吸力測(cè)試方法較多,其中濾紙法最為快捷、簡(jiǎn)便且量程大。本文取陜西涇陽(yáng)L1和L5黃土樣,在ASTM D5298-10的基礎(chǔ)上,研究濾紙法測(cè)試基質(zhì)吸力的操作過(guò)程,重點(diǎn)對(duì)土樣的制備和試驗(yàn)條件、濾紙的稱(chēng)量、平衡時(shí)間等關(guān)鍵步驟進(jìn)行分析和改進(jìn),將測(cè)試結(jié)果與其他方法進(jìn)行對(duì)比,主要結(jié)論有:1)實(shí)驗(yàn)密封條件采用錫紙包裹并蠟封的方法代替ASTM D5298-10推薦的密封罐,解決了密封罐易造成密封不嚴(yán)及取放土樣不便的問(wèn)題,密封結(jié)果更為理想;2)由鋁盒或者保鮮袋為濾紙的容器稱(chēng)量濾紙改為直接將濾紙放在天平托盤(pán)上稱(chēng)量,提高了稱(chēng)量濾紙的精度;3)對(duì)于同一種土,多組環(huán)刀聯(lián)合測(cè)試與只采用一組環(huán)刀測(cè)試相比,更易于操作,且減小了操作過(guò)程中的誤差;4)土樣與濾紙的水勢(shì)平衡時(shí)間與土樣的干密度關(guān)系小,與土樣的含水率關(guān)系較大,含水率越大平衡時(shí)間越短,反之,平衡時(shí)間越長(zhǎng),對(duì)于涇陽(yáng)L1和L5黃土,土樣含水率小于5%時(shí),建議平衡時(shí)間13天以上;土樣含水率介于5%~20%之間,建議平衡時(shí)間為10天以上;含水率大于20%時(shí),建議平衡時(shí)間為5天以上;5)分別采用Gardner模型、Van Genuchten模型和FredlundXing模型對(duì)濾紙法所獲基質(zhì)吸力及土樣實(shí)際含水率進(jìn)行SWCC擬合,FredlundXing模型擬合度最高;6)通過(guò)將已有采用張力計(jì)、壓力板儀、壓力膜儀、滲析法及濾紙法等測(cè)得的黃土SWCC與本文濾紙法測(cè)試結(jié)果對(duì)比,證明本文推薦的方法和所測(cè)試的結(jié)果可靠性高且在全基質(zhì)吸力范圍內(nèi)均較為適用。
[Abstract]:The fundamental difference between unsaturated soil and saturated soil is that the pore water pressure in unsaturated soil is negative. The difference between pore pressure and negative pore water pressure is defined as matrix suction, which is used to reflect the stress characteristics of unsaturated soil. The relation curve between matrix suction and soil moisture content is called the soil-water characteristic curve (Soil-Water Characteristic Curve), which is an important constitutive relation of unsaturated soil. It can be used to analyze and predict the deformation, strength and permeability of soil. Therefore, SWCC is the basis of unsaturated soil research. There are many methods of matrix suction measurement, among which filter paper method is the most rapid, simple and has a large measuring range. On the basis of ASTM D5298-10, the operating process of filter paper method for measuring the suction of the matrix was studied, and the preparation and test conditions of the soil samples, the weighing of filter paper, were studied in this paper, taking the loess samples of Jingyang, Shaanxi Province, as well as the L _ 5 loess samples, and based on ASTM D5298-10. The key steps, such as balance time, are analyzed and improved, and the test results are compared with other methods. The main conclusions are as follows: 1) the experimental sealing conditions are replaced by the seal tank recommended by ASTM D5298-10. The problem that the sealing tank is easy to be sealed and the soil sample is not easy to be taken is solved, and the sealing result is more ideal. 2) the weighing filter paper is changed from the container weighing filter paper of aluminum box or fresh-keeping bag to the weighing paper directly on the balance tray, which improves the accuracy of weighing filter paper; 3) for the same soil, it is easier to operate and the error in the operation process is reduced compared with that of using only one group of ring knives. 4) the water potential equilibrium time of soil sample and filter paper has little relationship with dry density of soil sample, and has a greater relation with soil sample moisture content. The larger the water content is, the shorter the equilibrium time is, otherwise, the longer the equilibrium time is, the longer the balance time is, and the longer the balance time is, the longer the balance time is for Jingyang L1 and L5 loess. When the moisture content of soil sample is less than 5, it is suggested that the balance time be more than 13 days. The water content of soil sample is between 5% and 20%, and the suggested equilibrium time is more than 10 days, and when the moisture content is more than 20, the suggested equilibrium time is more than 5 days. 5) Gardner model, Van Genuchten model and FredlundXing model were used to fit the matrix suction and soil sample moisture content obtained by filter paper method respectively. FredlundXing model had the highest fitting degree. 6) the SWCC of loess measured by tension meter, pressure plate instrument, pressure film meter, dialysis method and filter paper method are compared with the results of filter paper method in this paper. It is proved that the proposed method and the measured results are reliable and applicable in the whole matrix suction range.
【學(xué)位授予單位】：長(zhǎng)安大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TU444

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 侯曉坤;翟張輝;晁建紅;張常亮;李萍;李同錄;;黃土非飽和濕陷變形的計(jì)算模型[J];水文地質(zhì)工程地質(zhì);2016年03期

2 劉朋飛;殷躍平;李濱;孫一博;;非飽和黃土干濕循環(huán)土水特征曲線試驗(yàn)及滲透系數(shù)預(yù)測(cè)[J];中國(guó)地質(zhì)災(zāi)害與防治學(xué)報(bào);2015年04期

3 鄭娟;趙麗婭;劉保健;;非飽和黃土的土水特征曲線試驗(yàn)研究[J];南水北調(diào)與水利科技;2015年06期

4 楊益彪;詹良通;王順玉;陳云敏;趙云飛;;封頂覆蓋黃土氣體滲透特性測(cè)試及填埋氣一維運(yùn)移分析[J];巖土力學(xué);2015年07期

5 袁志輝;倪萬(wàn)魁;劉茹;李煥煥;;基于吸應(yīng)力的非飽和黃土抗剪強(qiáng)度研究[J];合肥工業(yè)大學(xué)學(xué)報(bào)(自然科學(xué)版);2015年05期

6 黃志全;岳康興;李幻;李磊;;濾紙法測(cè)定非飽和膨脹土土水特征曲線試驗(yàn)[J];南水北調(diào)與水利科技;2015年03期

7 許淑珍;白曉紅;馬富麗;;利用MATLAB擬合壓實(shí)黃土土水特征曲線的研究[J];太原理工大學(xué)學(xué)報(bào);2015年01期

8 吳義高;孫德安;;淮安膨脹土的土水特性[J];上海大學(xué)學(xué)報(bào)(自然科學(xué)版);2014年02期

9 邵恩慶;張虎元;孔應(yīng)德;;蘭州地區(qū)垃圾填埋場(chǎng)黃土騰發(fā)蓋層降水入滲模擬[J];環(huán)境工程學(xué)報(bào);2014年03期

10 褚峰;邵生俊;陳存禮;;干密度和豎向應(yīng)力對(duì)原狀非飽和黃土土水特征影響的試驗(yàn)研究[J];巖石力學(xué)與工程學(xué)報(bào);2014年02期

相關(guān)博士學(xué)位論文 前2條

1 趙彥旭;壓實(shí)黃土增濕變形的非飽和土力學(xué)研究[D];蘭州大學(xué);2010年

2 金旭;非飽和原狀土土—水特征曲線及本構(gòu)模型的研究[D];北京交通大學(xué);2010年

相關(guān)碩士學(xué)位論文 前8條

1 孫釗;非飽和定邊黃土滲透沖蝕試驗(yàn)研究[D];長(zhǎng)安大學(xué);2015年

2 劉蒙蒙;涇陽(yáng)縣南塬黃土邊坡滲透系數(shù)變異性分析[D];長(zhǎng)安大學(xué);2015年

3 劉茹;基于土-水特征曲線的黃土壓縮特性試驗(yàn)研究[D];長(zhǎng)安大學(xué);2014年

4 江耀;非飽和黃土特征曲線的研究[D];蘭州大學(xué);2012年

5 劉新華;黃土狀填土應(yīng)力相關(guān)的土水特征曲線及其強(qiáng)度[D];太原理工大學(xué);2012年

6 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

7 張昭;非飽和土的滲透函數(shù)試驗(yàn)研究及其應(yīng)用[D];西安理工大學(xué);2009年

8 盧靖;非飽和黃土水分遷移問(wèn)題的試驗(yàn)研究[D];西安建筑科技大學(xué);2006年

，

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