本文選題：沿空留巷　切入點(diǎn)：堅(jiān)硬頂板　出處：《安徽理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：切頂卸壓手段在解決堅(jiān)硬頂板下留巷困難問題方面獨(dú)樹一幟,本文以潘一東礦1252(1)工作面為研究背景,采用相似模擬、數(shù)值模擬、理論分析、工業(yè)實(shí)測(cè)等方法,深入探討了切頂卸壓在堅(jiān)硬頂板下留巷的作用機(jī)理。采用相似模擬手段形象再現(xiàn)了切頂與否,在沿空留巷巷道開挖、開挖穩(wěn)定、一次開挖、一次開挖穩(wěn)定、二次開挖五個(gè)時(shí)期中巷道圍巖及應(yīng)力變化情況。對(duì)比分析切頂與否在五個(gè)時(shí)期圍巖應(yīng)力及巖層垮落變化的不同,得出切頂在后三個(gè)時(shí)期的作用比較明顯,其改變了硬巖層跨斷方式,防止采空區(qū)大面積懸頂后,突然下沉而產(chǎn)生巨大載荷,可有效緩解巷旁支護(hù)阻力壓力集中問題。運(yùn)用數(shù)值模擬手段進(jìn)一步對(duì)比分析切頂與否圍巖應(yīng)力場(chǎng)及位移場(chǎng)的變化,進(jìn)一步證明切頂后可緩解圍巖變形過大,墻體應(yīng)力集中等問題。同時(shí),模擬分析在不同切頂高度、不同切頂角度、不同采高條件下,巷道圍巖應(yīng)力及位移的變化趨勢(shì),并針對(duì)1252(1)工作面提出了最優(yōu)切頂角度35°,最優(yōu)切頂高度20m,這與實(shí)踐相一致。在采用相似模擬、數(shù)值模擬分析的基礎(chǔ)上,運(yùn)用理論手段以冒落帶內(nèi)綜合強(qiáng)度30MPa為臨界值,判定其是否可自行冒落并能否充填滿采空區(qū)為一依據(jù);以裂隙帶內(nèi)是否存在關(guān)鍵層作為另一依據(jù),參照這兩依據(jù)將頂板劃分為4類巖層。結(jié)合1252(1)工作面實(shí)際地質(zhì)條件判定其屬于第Ⅱ類巖層。以第Ⅱ類巖層為基礎(chǔ),建立結(jié)構(gòu)力學(xué)模型,分析頂板極限垮落層位高度以及冒落帶高度,推導(dǎo)出關(guān)鍵塊體B破斷時(shí)特征長(zhǎng)度與厚度。建立Ⅱ類巖層留巷力學(xué)模型,推導(dǎo)出巷旁臨界支護(hù)阻力公式,得出支護(hù)阻力與懸頂距X2成正比,并采用敏感性分析手段,得出塊體B特征長(zhǎng)度L與懸頂距對(duì)巷旁支護(hù)阻力影響較大,針敏感度較大參數(shù),提出Ⅱ類覆巖結(jié)構(gòu)下巷道的維護(hù)措施。在工程實(shí)踐中運(yùn)用上述分析的巷道維護(hù)手段,通過現(xiàn)場(chǎng)位移應(yīng)力實(shí)測(cè)以及巷道維護(hù)實(shí)照的拍攝,切實(shí)有效的表明,運(yùn)用切頂卸壓手段可弱化堅(jiān)硬頂板下來壓集中問題,減少巷道圍巖移近量,有效保護(hù)巷道完整性,保證堅(jiān)硬頂板下留巷成功。
[Abstract]:The method of roof cutting and pressure relief is unique in solving the difficult problem of retaining roadway under hard roof. In this paper, taking the 1252DU 1 face of Panyidong Mine as the research background, similar simulation, numerical simulation, theoretical analysis, industrial measurement and so on are adopted. In this paper, the mechanism of cutting pressure relief under hard roof is deeply discussed. The similar simulation method is used to reproduce the roof cutting or not, and the roadway along the goaf is excavated, the excavation is stable, the first excavation is stable, the first excavation is stable, the first excavation is stable, the other is the stability of the excavation. The change of surrounding rock and stress of roadway during the five periods of secondary excavation, the difference of stress of surrounding rock and rock collapse in five periods of roof cutting or not is analyzed, and it is concluded that the effect of roof cutting in the latter three periods is obvious. It has changed the hard rock stratum span and broken way, preventing the huge load after the large area suspended roof of the goaf, suddenly sinking and producing the huge load. The stress field and displacement field of surrounding rock in roof cutting or not are further compared and analyzed by numerical simulation. It is further proved that the deformation of surrounding rock can be alleviated after roof cutting. At the same time, the variation trend of surrounding rock stress and displacement of roadway under different roof cutting height, different cutting angle and different mining height is simulated. The optimum roof cutting angle 35 擄and the optimum cutting height 20 m are put forward for 1252Q1) working face, which is consistent with practice. On the basis of similar simulation and numerical simulation analysis, the critical value is 30 MPA in the caving zone by theoretical means. It is determined whether it can caving on its own and whether it can fill up the goaf, and whether there is a critical layer in the fissure zone as another basis, According to these two bases, the roof is divided into four types of rock formations, combined with the actual geological conditions of 1252Q1) face, it is determined that it belongs to the second type rock stratum. Based on the second type rock stratum, the structural mechanics model is established. Based on the analysis of the height of roof limit collapse and the height of caving zone, the characteristic length and thickness of key block B are deduced. The mechanical model of retaining roadway of type 鈪，

本文編號(hào)：1629493