本文選題：厚硬頂板　切入點(diǎn)：特厚煤層　出處：《中國(guó)礦業(yè)大學(xué)》2016年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：沖擊礦壓是煤礦開(kāi)采中最為典型的煤巖動(dòng)力災(zāi)害之一。具有厚硬頂板的特厚煤層孤島煤柱,沖擊礦壓的危害則更加嚴(yán)重,且相關(guān)方面的研究較少。為此,本文通過(guò)理論分析、數(shù)值模擬及現(xiàn)場(chǎng)實(shí)踐等方法對(duì)厚硬頂板孤島煤柱沖擊礦壓發(fā)生機(jī)理及特厚煤層巷道錯(cuò)層防治技術(shù)進(jìn)行了系統(tǒng)研究。理論推導(dǎo)可知,隨著工作面四鄰開(kāi)采條件由實(shí)體煤到四側(cè)均采空的不斷惡化,頂板內(nèi)應(yīng)力集中程度逐漸增加,彎曲變形能積聚速率逐步上升,特別是具有堅(jiān)硬厚層頂板的孤島煤柱更易形成具有大面積懸頂?shù)拈L(zhǎng)臂“T”形覆巖結(jié)構(gòu),其巖層活動(dòng)范圍、劇烈程度大,容易在周?chē)删騽?dòng)力擾動(dòng)作用下頂板破裂形成大能量強(qiáng)礦震震動(dòng)以應(yīng)力波的形式對(duì)煤柱施加動(dòng)載荷,而孤島煤柱在大面積懸頂?shù)膴A持作用下已經(jīng)處于高應(yīng)力狀態(tài),原本較高的靜載與動(dòng)載相疊加超過(guò)煤巖體極限強(qiáng)度,導(dǎo)致處于極限狀態(tài)的煤巖體系統(tǒng)失穩(wěn)破壞,引起大規(guī)模的沖擊動(dòng)力災(zāi)害,即由高靜載主導(dǎo)—?jiǎng)虞d誘發(fā)的動(dòng)靜載疊加誘沖機(jī)理。孤島煤柱底煤應(yīng)力場(chǎng)計(jì)算結(jié)果表明,應(yīng)力差隨底煤深度的增加而減小,應(yīng)力集中程度和應(yīng)力差隨應(yīng)力集中系數(shù)的改變變化明顯。底煤中同時(shí)存在應(yīng)力降低區(qū)和應(yīng)力變化降低區(qū),其可分別表示為0.1q應(yīng)力和1%應(yīng)力變化率等值線(xiàn)包絡(luò)外的區(qū)域。而非均布應(yīng)力是導(dǎo)致巷道支護(hù)結(jié)構(gòu)損壞,巷道變形的主因之一,因此錯(cuò)層巷道應(yīng)布置在應(yīng)力降低區(qū)和應(yīng)力變化降低區(qū)的疊加區(qū)域以?xún)?nèi)。定義0.1q和1%等值線(xiàn)分別為底煤應(yīng)力降低區(qū)和應(yīng)力變化降低區(qū)邊界,其與豎直線(xiàn)之間的夾角則定義為應(yīng)力降低角kq和應(yīng)力變化降低角sq。應(yīng)力集中系數(shù)k與二者線(xiàn)性正相關(guān),且在k11時(shí),k sq(27)q,因此多數(shù)情況應(yīng)以sq為綜合應(yīng)力影響角f,合理錯(cuò)距為1 2 0l(28)(h(10)h)tanf-x。并以1210孤島面兩巷錯(cuò)層布置工程實(shí)踐驗(yàn)證了錯(cuò)距計(jì)算的合理性。通過(guò)FLAC3D數(shù)值模擬計(jì)算得到1210孤島煤柱和下山孤島煤柱的應(yīng)力集中系數(shù)分別為3.8和2.8,驗(yàn)證了孤島煤柱應(yīng)力集中程度高、沖擊危險(xiǎn)性強(qiáng)的結(jié)論。通過(guò)對(duì)各方案的圍巖應(yīng)力及變形情況分析對(duì)比發(fā)現(xiàn)專(zhuān)用回風(fēng)巷錯(cuò)層布置方案處于上方采空區(qū)的應(yīng)力降低區(qū)下,巷道圍巖應(yīng)力及變形量要遠(yuǎn)小于其他各方案,對(duì)于防沖十分有利。以孟巴礦1108孤島面沖擊事故為背景分析了厚硬頂板孤島煤柱沖擊發(fā)生的機(jī)理,結(jié)合1210孤島面兩巷錯(cuò)層布置工程實(shí)例,驗(yàn)證了錯(cuò)層防沖技術(shù)的合理性與優(yōu)越性。
[Abstract]:Rock burst is one of the most typical coal and rock dynamic disasters in coal mining. With thick and hard roof thick coal seams with isolated island pillar, the impact pressure is more serious, and the related research is less. Numerical simulation and field practice have been carried out to study systematically the mechanism of rock burst and the prevention and cure technology of roadway dislocation in thick coal seam by means of thick and hard roof isolated island coal pillar. With the deterioration of mining conditions from solid coal to four sides of the face, the degree of stress concentration in the roof increases gradually, and the accumulation rate of bending deformation energy increases gradually. In particular, the isolated island coal pillar with hard and thick roof is more likely to form a long-arm "T" overburden structure with a large area of suspended roof, which has a wide range of strata activity and a large degree of intensity. It is easy to crack the roof under the action of the surrounding mining dynamic disturbance to form a large energy strong mine earthquake vibration to exert dynamic load on the coal pillar in the form of stress wave, while the isolated island coal pillar is already in a high stress state under the action of a large area of suspended roof. The superposition of static load and dynamic load exceeds the limit strength of coal and rock mass, which leads to the instability of coal and rock mass system in the limit state and causes large-scale impact dynamic disaster. The stress field calculation results show that the stress difference decreases with the increase of coal depth. The degree of stress concentration and stress difference change obviously with the change of stress concentration coefficient. It can be expressed as the area outside the isoline envelope of 0. 1q stress and 1% stress change rate, and non-uniform stress is one of the main causes of roadway support structure damage and roadway deformation. Therefore, the staggered roadway should be arranged within the superposition area of the stress reduction area and the stress change reduction area. The boundary of the 0. 1q and 1% isolines is defined as the bottom coal stress reduction area and the stress change reduction area, respectively. The angle between it and the vertical line is defined as the stress reduction angle KQ and the stress change reduction angle sq.Stress-concentration factor k is positively correlated with the two factors. In most cases, sq should be taken as the comprehensive stress influence angle f, and the reasonable error distance is 120 l0 / 28 / 10 / 10 / h ~ (tanf-x). The rationality of the calculation of the fault distance is verified by the engineering practice of the layout of two roadways on the 1210 isolated island surface. The calculation is obtained by FLAC3D numerical simulation. The stress concentration factors of Gudao coal pillar and Xiashan Gudao coal pillar are 3.8 and 2.8, respectively. It is verified that the stress concentration degree of Gudao coal pillar is high. Through the analysis and comparison of the surrounding rock stress and deformation of each scheme, it is found that the staggered layer arrangement of the special return air roadway is under the stress reduction area of the upper goaf. The stress and deformation of surrounding rock of roadway are much smaller than those of other schemes, which is very beneficial to anti-scour. Based on the impact accident of 1108 isolated island surface in Mengba Mine, the mechanism of impact of thick and hard roof isolated island coal pillar is analyzed. The rationality and superiority of the anti-scour technology of the staggered layer are verified by the example of 1210 isolated island plane two roadway staggered layer arrangement engineering.
【學(xué)位授予單位】：中國(guó)礦業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：TD324

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本文編號(hào)：1615483