【摘要】：經過多年的發(fā)展,厚煤層已經成為我國煤炭開采中的主力煤層,可占總產量的45%左右,因此“三下”等特殊地質條件下厚煤層的開采是一直以來備受關注的問題。尤其是厚度為8 m以上的特厚煤層,由于自身厚度大,開采過程對覆巖的破壞嚴重,巖層控制難度很大。盡管充填開采已被證明是開采“三下”壓煤的有效途徑,但是目前尚未形成一套成熟的可以實現(xiàn)特厚煤層高回采率和高充實率的充填開采方法。鑒于此,本文針對特厚煤層提出了上向分層長壁逐巷膠結充填開采技術方法,采用實驗室試驗、力學分析、物理模擬、數(shù)值模擬及現(xiàn)場應用相結合的研究方法,分析了該方法中的關鍵技術參數(shù)如開采聯(lián)絡巷合理間距和充填擋墻側壓力,研發(fā)了配套的膠結充填材料并研究了配比對材料流變及力學性能的影響規(guī)律,研究了采用此種方法開采特厚煤層的過程中頂板控制機理,分析了各分層開采覆巖移動破壞和采場礦壓顯現(xiàn)規(guī)律,并將研究成果進行了工程應用。論文取得的創(chuàng)新性成果如下:(1)研發(fā)了采用矸石、粉煤灰及混合膠結料為原料的膠結充填材料,采用以坍落度換算屈服應力的方法研究了配比對材料流變性能的影響規(guī)律,得到了在配比和養(yǎng)護齡期耦合作用下充填材料強度和泊松比的演化特征,以實測數(shù)據(jù)為基礎建立了基于改進的BP神經網絡的膠結充填材料性能預測模型,揭示了各影響因素的作用機理。(2)建立了頂板動態(tài)非均勻組合彈性地基梁模型,研究了各分層開采過程中頂板移動變形特征,揭示了特厚煤層上向分層長壁逐巷膠結充填開采頂板移動控制機理,提出了開采不同分層數(shù)對應的充填材料性能要求;并基于膠結充填材料流變性能的時間相關特性,計算得出了充填擋墻側壓力隨時間的演化規(guī)律。(3)采用物理模擬和數(shù)值模擬相結合的方法,分析了不同分層開采過程中的覆巖垂直位移、裂隙發(fā)育和應力演化規(guī)律,揭示了采用上向分層長壁逐巷膠結充填技術開采特厚煤層時覆巖移動破壞與采場礦壓控制原理,研究表明第五分層和第六分層開采對覆巖造成的擾動明顯大于之前各分層的開采。(4)提出了特厚煤層上向分層長壁逐巷充填開采技術方法,設計了與此方法相配套的生產系統(tǒng)和開采工藝,并成功應用于公格營子煤礦含水層下厚度為21 m的特厚煤層開采實踐,現(xiàn)場實測數(shù)據(jù)表明工程應用效果良好。
[Abstract]:After years of development, thick coal seam has become the main coal seam in coal mining in China, which can account for about 45% of the total production. Therefore, the mining of thick coal seam under special geological conditions such as "Sanxia" has always been a problem of great concern. Especially for the extra thick coal seam with thickness of more than 8 m, because of its large thickness, the mining process has serious damage to the overburden rock, and it is very difficult to control the strata. Although the backfill mining has been proved to be an effective way to extract the "three down" coal, there is not yet a set of mature filling mining methods which can realize the high recovery rate and the high enrichment rate of the extra thick coal seam. In view of this, this paper puts forward the technology of cemented filling mining for the super thick coal seam, which combines laboratory test, mechanical analysis, physical simulation, numerical simulation and field application, using the method of cementing and filling mining method of upward stratified long wall by roadway, using the method of combining laboratory test, mechanical analysis, physical simulation, numerical simulation and field application. The key technical parameters of this method, such as reasonable spacing of mining joint roadway and side pressure of filling retaining wall, are analyzed. The matching cemented filling materials are developed and the influence of proportioning on material rheology and mechanical properties is studied. The mechanism of roof control in the process of mining extra thick coal seam with this method is studied. The law of overburden movement and failure and stope pressure behavior in each layer mining are analyzed, and the research results are applied in engineering. The innovative results obtained in this paper are as follows: (1) the cemented filling materials using gangue, fly ash and mixed binder as raw materials are developed, and the effect of proportioning on the rheological properties of the materials is studied by the method of slump conversion yield stress. The evolution characteristics of the strength and Poisson's ratio of filling materials under the coupling of ratio and curing age are obtained. Based on the measured data, the performance prediction model of cemented filling materials based on improved BP neural network is established. The mechanism of the influence factors is revealed. (2) the dynamic composite elastic foundation beam model of roof is established, and the characteristics of roof movement and deformation during the mining process are studied. This paper reveals the control mechanism of roof movement in cemented filling mining with long wall by roadway, and puts forward the performance requirements of filling material corresponding to different layers of mining, and based on the time-dependent characteristics of rheological properties of cemented filling materials, The evolution law of lateral pressure of filling retaining wall with time is obtained. (3) the vertical displacement, crack development and stress evolution of overburden in different stratified mining process are analyzed by combining physical simulation with numerical simulation. This paper reveals the principle of overlying rock movement destruction and stope pressure control when mining extra thick coal seam by cemented filling technology of upward stratified long wall by roadway. The study shows that the disturbance caused by the fifth and sixth stratification mining to the overburden rock is obviously greater than that of the previous stratified mining. (4) the technique of filling up the long wall of the super thick coal seam by roadway is put forward. The production system and mining technology matched with this method are designed and successfully applied to the mining practice of the super-thick coal seam with a thickness of 21 m under the aquifer of Gonggeyingzi Coal Mine. The field measured data show that the engineering application effect is good.
【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】：TD325;TD823.7
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本文編號：2292022