發(fā)布時間：2018-03-17 15:00

  本文選題：高瓦斯煤層群　切入點：卸壓開采　出處：《中國礦業(yè)大學》2017年博士論文　論文類型：學位論文

【摘要】：卸壓開采結合瓦斯抽采是實現(xiàn)高瓦斯煤層群煤與瓦斯共采的有效方法。而應力-裂隙-滲流耦合作用機理是高瓦斯煤層群卸壓開采的基礎問題,直接影響著卸壓開采的成敗和效果。為此,論文采用理論分析、實驗室實驗、數(shù)值模擬以及現(xiàn)場實測相結合的研究方法建立了煤層群重復采動應力-裂隙-滲流耦合模型,分析了其耦合作用機理,提出了卸壓開采效果評價方法,掌握了采動圍巖穩(wěn)定與滲透率演化的時空關系。研究成果為高瓦斯煤層群煤與瓦斯共采提供了理論基礎。取得了如下主要創(chuàng)新成果:(1)研制了各向異性采動煤巖體滲透測試實驗系統(tǒng),揭示了不同損傷裂隙煤巖體應力-滲流作用機理。實現(xiàn)了煤體軸向和徑向應力滲透率的測試。提出了覆巖“三帶”損傷裂隙煤巖體試樣分類及制備方法,測試了不同損傷煤巖體滲透率隨工作面開采及瓦斯抽采的時空演化規(guī)律,建立了重復采動作用下煤巖體應力-滲透率模型,采用絕對和相對應力敏感性系數(shù)評價了煤巖樣的應力敏感性及其演化特征。(2)提出了裂隙煤巖體流固耦合參數(shù)的數(shù)值模擬表征方法,揭示了應力-裂隙-滲流的耦合作用機理。構建了不同裂隙結構煤體滲透率的離散元數(shù)值模型,提出了節(jié)理裂隙數(shù)值模擬參數(shù)的標定方法,研究了煤體滲透特性的各向同性和各向異性特征,揭示了煤體裂隙對滲透率應力敏感性的內(nèi)在影響機理;掌握了裂隙形態(tài)及參數(shù)與裂隙煤樣滲透率的內(nèi)在聯(lián)系。分析了采動裂隙煤樣三軸流固耦合應力-裂隙-滲流演化特征,闡明了偏應力條件下采動裂隙煤樣軸向滲透率對圍壓及軸壓敏感性差異的主要原因。(3)建立了重復采動覆巖應力-裂隙-滲流耦合模型,提出了卸壓開采及瓦斯抽采參數(shù)的設計方法。運用實驗室三軸流固耦合實驗及現(xiàn)場煤層瓦斯抽采實測驗證了模型的可靠性。實現(xiàn)了煤層群卸壓開采覆巖三帶滲透率演化規(guī)律及分布特征的定量分析,掌握了卸壓開采及瓦斯抽采過程中瓦斯的滲流路徑及瓦斯壓力的分布特征;確定了韓城礦區(qū)及淮南礦區(qū)上、下保護層開采的最小采厚及合理采厚,闡明了層間距與保護層采高的相關關系;設計了卸壓瓦斯抽采鉆孔布置方案。(4)建立了煤層群卸壓開采效果評價模型,揭示了卸壓開采覆巖運動的時空演化關系。建立了瓦斯分源模型,提出了卸壓開采效果評價方法;定量分析了采空區(qū)垮落帶各區(qū)域的壓實時間、壓實程度及滲透率分布特征,掌握了卸壓開采圍巖滲透率的時空演化規(guī)律;闡明了采空區(qū)垮落帶壓實應力、壓實時間及滲透率三者之間的內(nèi)在關系。
[Abstract]:Pressure relief gas drainage combined mining is an effective method for the realization of coal and gas outburst coal seams in high gas mining. And the stress fracture seepage coupling mechanism is the basic problem of coal seam gas pressure relief mining, directly affects the success or failure of unloading and effect of mining. Therefore, this paper uses theoretical analysis, laboratory experimental research, numerical simulation and field measurement was established with the coal seam group repeated mining stress fracture seepage coupling model, analyzes the coupling mechanism, the pressure relief mining effect evaluation method, grasp the temporal and spatial relationship between surrounding rock stability and permeability evolution of mining. Research results for high gassy coal seams coal and gas extraction provides a theoretical basis. The main innovative achievements are as follows: (1) developed anisotropic mining coal rock permeability testing system, reveals the different damage of fractured coal and rock stress seepage for With the implementation of coal. The mechanism of axial and radial stress permeability test. The overburden three zones of rock fracture damage of coal sample preparation and classification methods, different damage of coal rock mass permeability with mining and gas drainage of the time-space evolution of the established test, repeated mining of coal and rock under the action of stress permeability model, the absolute and relative stress sensitivity coefficient to evaluate the coal rock stress sensitivity and its evolution. (2) proposed to characterize the numerical method of coal mass flow solid coupling simulation, coupling mechanism of stress fracture seepage was revealed. Constructed the discrete element numerical model fracture structure of coal permeability, proposed joint numerical simulation parameter calibration method, studied the permeability of coal body in isotropic and anisotropic characteristics, reveals the fissures of coal permeability should be sensitive to the force The internal influence mechanism; grasp the inner link of fracture morphology and fracture parameters and the permeability of coal sample. The analysis of mining fissure coal three axial flow solid coupling seepage force characteristics evolution fracture, the deviatoric fissure coal permeability on axial confining pressure and axial pressure sensitivity was the main reason of the difference. Under the condition of force production (3) established a repeat of overlying rock fissure seepage stress coupling model, put forward the design method of mining pressure unloading and gas drainage parameters. Using the laboratory three axial flow solid coupling experiment and field methane drainage proved the reliability of the model. The unloading of coal seams the quantitative distribution of overburden pressure with three permeability evolution mining analysis, grasp the distribution characteristics of the seepage path and gas pressure relief and gas drainage in the process of mining gas; the Hancheng mine and Huainan mine, under the protection layer Minimum mining thickness and reasonable mining thickness mining, illustrates the layer spacing and the protective layer mining high correlation; design of pressure relief gas drainage borehole layout scheme. (4) developed coal seams depressurized mining effect evaluation model, reveals the evolution of pressure relief mining overburden movement. The relationship between the establishment of a gas the source model, put forward the depressurized mining effect evaluation method; quantitative analysis of the goaf caving zone compaction time of each area, the degree of compaction and permeability distribution characteristics, grasp the depressurized mining temporal rock permeability evolution law; clarifies the caving zone in goaf compaction stress, relationship between compaction the time and the permeability of the three.

【學位授予單位】：中國礦業(yè)大學
【學位級別】：博士
【學位授予年份】：2017
【分類號】：TD712.6
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本文編號：1625243