【摘要】：裂隙巖體是自然界中廣泛存在的一種具有災(zāi)害隱患的巖體,其滲流失穩(wěn)是導(dǎo)致巖體工程破壞,甚至大型地質(zhì)災(zāi)害的重要原因。目前,對于裂隙巖體滲透特性的研究,其室內(nèi)試驗(yàn)研究是不可或缺的重要技術(shù)手段,本文基于茅口灰?guī)r展開裂隙巖體滲流-應(yīng)力耦合試驗(yàn)的研究。試驗(yàn)巖樣取至湖南寧鄉(xiāng)煤炭壩,按國際巖石力學(xué)推薦標(biāo)準(zhǔn)加工成尺寸為Φ50×100mm的試件。首先,在RYL-600剪切流變儀上對完好巖樣進(jìn)行劈裂試驗(yàn),獲取裂隙茅口灰?guī)r樣,并取其中巖樣進(jìn)行循環(huán)加卸載試驗(yàn);其次,取裂隙巖樣在M T S 8 1 5巖石力學(xué)試驗(yàn)系統(tǒng)上進(jìn)行滲流-應(yīng)力耦合試驗(yàn),主要對裂隙巖體滲流-應(yīng)力耦合試驗(yàn)特性進(jìn)行研究。本文結(jié)合以上試驗(yàn)進(jìn)行研究并得到了以下相關(guān)結(jié)論:(1)本文首先完成了對于裂隙巖樣在相等最大法向應(yīng)力作用下的循環(huán)加卸載試驗(yàn),結(jié)果表明:裂隙法向閉合量雖然隨著循環(huán)加載次數(shù)的增加而增大,但最終裂隙并未完全閉合,而是有一定的裂隙張開度,這就是所謂的裂隙殘余閉合量。(2)針對同一批次裂隙巖樣進(jìn)行了同一軸壓不同圍壓作用下的滲流-應(yīng)力耦合試驗(yàn),結(jié)果表明:1)同一軸壓作用下,滲透系數(shù)與圍壓呈負(fù)冪律關(guān)系,隨圍壓增加不斷變小;體積應(yīng)力、滲透系數(shù)和孔隙壓三者能很好的滿足指數(shù)規(guī)律關(guān)系,同一孔隙壓作用下,隨體積增加滲透不斷減少;2)同一荷載作用下巖樣裂隙張開度大的滲透系數(shù)較張開度小的大;3)茅口灰?guī)r的裂隙流不滿足Darcy流,具有非D a r c y效應(yīng),且同一軸壓作用下,隨著圍壓的增大,非D a r c y效應(yīng)不斷增強(qiáng)。4)巖樣同一荷載作用下的非Darcy流滲透率較Darcy流的大;5)巖樣滲流過程中環(huán)向位移與孔隙壓差具有正相關(guān)的關(guān)系,孔隙壓差發(fā)生較大變化處,環(huán)向位移也會(huì)發(fā)生較大的變化;6)茅口灰?guī)r巖樣的裂隙流滿足溝槽模型,試驗(yàn)計(jì)算滲透系數(shù)值與理論計(jì)算值基本相符。(3)使用MATLAB軟件對滲流試驗(yàn)巖樣端面裂隙分布進(jìn)行分形維數(shù)計(jì)算,并與滲流試驗(yàn)結(jié)果進(jìn)行對比,結(jié)果表明相近隙寬下,裂隙分形維數(shù)越大,其滲透系數(shù)也越高。
[Abstract]:Fracture rock mass is a kind of rock mass with hidden danger in nature, and its seepage and loss stability is an important cause of rock mass engineering damage and even large geological disasters. At present, the laboratory test research on the permeability characteristics of fracture rock mass is an indispensable and important technical means. Based on the study of seepage-stress coupling test of fracture rock mass carried out by Maokou limestone, this paper is based on the study of seepage-stress coupling test of fracture rock mass. The test rock samples were taken to Ningxiang Coal Dam in Hunan Province and machined into 桅 50 脳 100mm specimens according to the international recommended standard of rock mechanics. Firstly, the split test of intact rock sample was carried out on RYL-600 shear rheometer, and the limestone sample of fissured Maokou was obtained, and the rock sample was taken for cyclic loading and unloading test. Secondly, the seepage-stress coupling test of fracture rock sample is carried out on M T S 815 rock mechanics test system, and the characteristics of seepage-stress coupling test of fracture rock mass are mainly studied. In this paper, combined with the above tests, the following conclusions are obtained: (1) in this paper, the cyclic loading and unloading test of fracture rock samples under the action of equal maximum normal stress is completed. The results show that although the normal closure of cracks increases with the increase of cyclic loading times, the cracks are not completely closed, but there is a certain degree of fracture opening. This is the so-called residual fracture closure. (2) the seepage-stress coupling tests under the same axial pressure and different confining pressure are carried out for the same batch of fracture rock samples. The results show that: 1) under the same axial compression, There is a negative power law relationship between permeability coefficient and confining pressure, which decreases with the increase of confining pressure. The relationship between volume stress, permeability coefficient and pore pressure can meet the exponential law very well. Under the same pore pressure, the permeability decreases with the increase of volume. 2) the permeability coefficient of rock sample fracture opening is larger than that of rock sample fracture under the same load. 3) the fracture flow of Maokou limestone does not satisfy Darcy flow and has non-Darcy effect, and under the same axial pressure, with the increase of confining pressure, The non-Darcy effect is increasing. 4) the permeability of non-Darcy flow under the same load is larger than that of Darcy flow. 5) there is a positive correlation between circumferential displacement and pore pressure difference in the seepage process of rock samples. When the pore pressure difference changes greatly, the circumferential displacement will also change greatly. 6) the fracture flow of Maokou limestone sample satisfies the trench model, and the calculated permeability coefficient is in good agreement with the theoretical value. (3) the fractal dimension of fracture distribution at the end face of seepage test rock sample is calculated by MATLAB software. Compared with the seepage test results, the results show that the larger the fractal dimension of the fracture is, the higher the permeability coefficient is.
【學(xué)位授予單位】：湖南科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU45

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 趙陽升,楊棟,鄭少河,胡耀青;三維應(yīng)力作用下巖石裂縫水滲流物性規(guī)律的實(shí)驗(yàn)研究[J];中國科學(xué)E輯:技術(shù)科學(xué);1999年01期

2 李培超,孔祥言,盧德唐;飽和多孔介質(zhì)流固耦合滲流的數(shù)學(xué)模型[J];水動(dòng)力學(xué)研究與進(jìn)展(A輯);2003年04期

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本文編號：2495075