【摘要】：瓦斯既是煤與瓦斯突出和瓦斯爆炸等煤礦災(zāi)害的主要誘因，同時(shí)又是一種不可再生的清潔能源，實(shí)現(xiàn)煤與瓦斯共采，不僅能提高煤礦安全生產(chǎn)水平，還將改善我國(guó)的能源結(jié)構(gòu)，對(duì)保障我國(guó)的能源安全有重要意義。而我國(guó)煤層普遍具有高瓦斯、低滲透、強(qiáng)吸附的特點(diǎn)，其中煤層滲透率比美國(guó)低2～3個(gè)數(shù)量級(jí)，瓦斯抽采難度極大，對(duì)煤層進(jìn)行人工增透成為實(shí)現(xiàn)煤與瓦斯共采的有效途徑。因此，充分認(rèn)識(shí)含瓦斯煤巖體變形破壞及其滲透性演化規(guī)律，定量描述煤層增透效果，對(duì)于實(shí)現(xiàn)煤與瓦斯共采具有極其重要的意義。本文針對(duì)含瓦斯煤變形破壞特征及其滲透行為，開(kāi)展了實(shí)驗(yàn)室試驗(yàn)、理論分析和數(shù)值模擬研究。主要研究?jī)?nèi)容如下： （1）利用MTS815和高壓瓦斯?jié)B透試驗(yàn)系統(tǒng)分別對(duì)型煤和原煤試樣進(jìn)行了單軸、三軸壓縮試驗(yàn)以及瓦斯?jié)B透試驗(yàn)，發(fā)現(xiàn)原煤的單軸和三軸抗壓強(qiáng)度分別為型煤的10.3倍和3.7倍，單軸和三軸彈性模量分別為型煤的75.1倍和12.7倍，型煤的塑性破壞形式和原煤的脆性破壞形式截然不同。型煤的初始滲透率是原煤的20倍，而破壞后型煤滲透率為原煤的90%。試驗(yàn)研究結(jié)果表明目前以型煤試驗(yàn)結(jié)果指導(dǎo)煤礦瓦斯抽采設(shè)計(jì)與施工極易造成重大安全隱患。 （2）利用三軸壓縮試驗(yàn)研究了不同瓦斯壓力下原煤的力學(xué)性質(zhì)，結(jié)果表明：隨著瓦斯壓力的增加，原煤剛度和強(qiáng)度逐漸降低，峰值破壞劇烈程度逐漸減弱，煤樣逐漸由脆性劈裂破壞向延性剪切破壞轉(zhuǎn)變。針對(duì)不同瓦斯壓力下煤巖體損傷破壞特征，，定義了煤巖體雙標(biāo)量損傷模型，同時(shí)考慮孔隙瓦斯壓力和吸附膨脹應(yīng)力作用，建立了新的含瓦斯煤彈性損傷本構(gòu)模型。 （3）利用三軸瓦斯?jié)B透試驗(yàn)研究了原煤損傷破壞過(guò)程中的滲透特征，結(jié)果表明：隨著瓦斯壓力的增加，原煤滲透率逐漸減��；滲透率與體積應(yīng)變呈良好的線性關(guān)系�；谄桨辶严读鲃�(dòng)方程建立了煤體滲透率與裂隙體積應(yīng)變的關(guān)系，考慮了瓦斯壓力和吸附瓦斯對(duì)裂隙體積應(yīng)變的影響，并首次引入了表征裂隙面粗糙度和裂隙迂曲度對(duì)滲透率影響的比例系數(shù)，建立了新的滲透率演化模型。 （4）基于所建立的損傷本構(gòu)和滲透率演化模型，自行開(kāi)發(fā)了相應(yīng)的三維彈性損傷和滲透性耦合分析有限元程序，實(shí)現(xiàn)了對(duì)采動(dòng)煤巖體的損傷及滲透率演化的定量描述。并以單一煤層開(kāi)采為例，對(duì)不同瓦斯壓力下采動(dòng)煤巖體損傷和滲透率演化特征進(jìn)行數(shù)值模擬。計(jì)算結(jié)果表明：隨工作面從30m推進(jìn)到150m，工作面前方煤體損傷范圍也由5m增加到30m左右，損傷區(qū)內(nèi)滲透率最大可增加2-3個(gè)量級(jí)，且相對(duì)于煤層瓦斯壓力1MPa的計(jì)算結(jié)果，煤層瓦斯壓力6MPa情況下工作面前方煤體損傷度最大增加19%，滲透率比率最大可增加85%。計(jì)算結(jié)果與工程實(shí)際基本吻合，可為煤礦瓦斯抽采設(shè)計(jì)提供科學(xué)指導(dǎo)。
[Abstract]:Gas is not only the main cause of coal and gas outburst and gas explosion, but also a kind of non-renewable clean energy. To realize coal and gas mining together can not only improve the level of coal mine safety production, but also improve the energy structure of our country. To safeguard our country's energy security has the important significance. However, coal seams in our country generally have the characteristics of high gas, low permeability and strong adsorption. The permeability of coal seam is 2 ~ 3 orders of magnitude lower than that of the United States, and it is very difficult to extract gas from coal seam. Artificial antipenetration of coal seam is an effective way to realize coal and gas mining. Therefore, it is of great significance to fully understand the law of deformation, failure and permeability evolution of gas-bearing coal and rock mass, and to describe quantitatively the antireflection effect of coal seam. In this paper, laboratory tests, theoretical analysis and numerical simulation are carried out on the characteristics of deformation and failure and permeability behavior of gas-bearing coal. The main research contents are as follows: (1) uniaxial, triaxial compression and gas permeation tests were carried out on briquette and raw coal samples using MTS815 and high pressure gas permeation test system, respectively. It is found that the uniaxial and triaxial compressive strength of raw coal is 10.3 and 3.7 times of that of briquette, and the uniaxial and triaxial modulus of elasticity is 75.1 and 12.7 times of that of briquette, respectively. The plastic failure form of briquette is different from that of brittleness failure of raw coal. The initial permeability of briquette is 20 times that of raw coal, but the permeability of broken briquette is 90% of that of raw coal. The experimental results show that the design and construction of gas drainage in coal mines are easy to be caused by the results of briquette tests. (2) the mechanical properties of raw coal under different gas pressure are studied by triaxial compression test. The results show that with the increase of gas pressure, the stiffness and strength of raw coal decrease gradually, and the intensity of peak failure decreases gradually. The coal samples gradually changed from brittle splitting failure to ductile shear failure. According to the damage and failure characteristics of coal and rock mass under different gas pressure, the dual scalar damage model of coal and rock mass is defined, and a new elastic damage constitutive model of gas-bearing coal is established considering the effect of pore gas pressure and adsorption expansion stress. (3) the permeability of raw coal during damage and failure is studied by triaxial gas permeation test. The results show that the permeability of raw coal decreases with the increase of gas pressure, and there is a good linear relationship between permeability and volume strain. Based on the plate fracture flow equation, the relationship between coal permeability and fracture volume strain is established, and the influence of gas pressure and gas adsorption on fracture volume strain is considered. A new permeability evolution model is established by introducing the proportional coefficient which represents the influence of fracture surface roughness and fracture roundness on permeability for the first time. (4) based on the damage constitutive model and permeability evolution model, a three dimensional finite element program for coupling analysis of elastic damage and permeability is developed, and the quantitative description of damage and permeability evolution of mining coal and rock mass is realized. Taking single coal seam mining as an example, the characteristics of damage and permeability evolution of mining coal and rock mass under different gas pressure are simulated numerically. The calculation results show that with the coal face advancing from 30 m to 150 m, the damage range of coal body in front of the face also increases from 5 m to 30 m, the maximum permeability in the damaged area can be increased by 2-3 orders of magnitude, and compared with the calculated result of 1MPa of coal seam gas pressure. Under the condition of gas pressure 6MPa in coal seam, the maximum damage degree of coal body in front of working face is increased by 19 percent, and the maximum permeability ratio can be increased by 85 percent. The calculated results are in good agreement with the engineering practice and can provide scientific guidance for the design of coal mine gas drainage.
【學(xué)位授予單位】：中國(guó)礦業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2013
【分類號(hào)】：TD712

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王金安,彭蘇萍,孟召平;巖石三軸全應(yīng)力應(yīng)變過(guò)程中的滲透規(guī)律[J];北京科技大學(xué)學(xué)報(bào);2001年06期

2 黃啟翔;;瓦斯壓力對(duì)煤巖材料全應(yīng)力-應(yīng)變過(guò)程瓦斯?jié)B透特性的影響[J];材料導(dǎo)報(bào);2010年16期

3 吳世躍,趙文,郭勇義;煤巖體吸附膨脹變形與吸附熱力學(xué)的參數(shù)關(guān)系[J];東北大學(xué)學(xué)報(bào);2005年07期

4 劉建坡;王洪勇;楊宇江;李元輝;;不同巖石聲發(fā)射定位算法及其實(shí)驗(yàn)研究[J];東北大學(xué)學(xué)報(bào)(自然科學(xué)版);2009年08期

5 胡千庭,蔣時(shí)才,蘇文叔;我國(guó)煤礦瓦斯災(zāi)害防治對(duì)策[J];礦業(yè)安全與環(huán)保;2000年01期

6 孫國(guó)文;黃滾;陳素娟;吳自立;;三維應(yīng)力場(chǎng)中煤滲透特性試驗(yàn)[J];礦業(yè)安全與環(huán)保;2011年05期

7 程瑞端,陳海焱,鮮學(xué)福,王國(guó)超;溫度對(duì)煤樣滲透系數(shù)影響的實(shí)驗(yàn)研究[J];煤炭工程師;1998年01期

8 孫培德,鮮學(xué)福,錢(qián)耀敏;煤體有效應(yīng)力規(guī)律的實(shí)驗(yàn)研究[J];礦業(yè)安全與環(huán)保;1999年02期

9 許江,鮮學(xué)福,杜云貴,張廣洋;含瓦斯煤的力學(xué)特性的實(shí)驗(yàn)分析[J];重慶大學(xué)學(xué)報(bào)(自然科學(xué)版);1993年05期

10 劉�？h;熊德國(guó);鮮學(xué)福;;電場(chǎng)對(duì)煤瓦斯吸附滲流特性的影響[J];重慶大學(xué)學(xué)報(bào)(自然科學(xué)版);2006年02期

相關(guān)博士學(xué)位論文 前2條

1 陶云奇;含瓦斯煤THM耦合模型及煤與瓦斯突出模擬研究[D];重慶大學(xué);2009年

2 李曉泉;含瓦斯煤力學(xué)特性及煤與瓦斯延期突出機(jī)理研究[D];重慶大學(xué);2010年

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