【摘要】：娘姆特煤礦首采區(qū)煤層屬于大傾角煤層,目前尚未開采,礦區(qū)地表賦存有20m-70m厚的多年凍土層,多年凍土層下大傾角煤層開采工作面礦壓問題目前尚無人研究,凍土的特殊性決定了工作面礦壓規(guī)律的特殊性。多年凍土層對礦井礦壓規(guī)律的影響主要表現(xiàn)在其破斷使工作面面臨沖擊礦壓現(xiàn)象,從而對井下生產(chǎn)人員的人身安全造成嚴重威脅。因此,對娘姆特煤礦首采綜放工作面礦壓規(guī)律的研究極為迫切。文章主要通過研究多年凍土層物理力學性質與溫度的關系,結合實驗手段分析研究娘姆特首采工作面覆巖運移規(guī)律和應力分布規(guī)律。研究表明,工作面上覆凍土層溫度分布受埋深影響,地表季融層溫度變化受季節(jié)溫度影響較大,隨深度加深,夏季與冬季凍土層溫度分布規(guī)律趨于一致,冬季凍土層溫度梯度約為0.1℃/m,夏季凍土層溫度梯度約為0.16℃/m,多年凍土層的物理力學性質隨溫度改變也相應改變,與溫度近似成線性關系。通過理論計算分析,得出首采面上覆多年凍土層破斷步距與溫度之間的函數(shù)關系式,并指出多年凍土層破斷時對下方覆巖造成能量沖擊,產(chǎn)生的彎曲能量指數(shù)大小與多年凍土層溫度有關。通過建立數(shù)值模型,模擬研究得出首采工作面開采后圍巖的位移分布呈帶狀不對稱分布,工作面的推進會造成圍巖的變形破壞,多年凍土層下部產(chǎn)生明顯離層現(xiàn)象,離層高度受凍土層溫度影響,夏季達到1.6m,冬季達到1.38m;多年凍土層的下沉量隨著開采范圍增加線性增加。開采范圍越大,地表多年凍土層受采動影響越劇烈,隨著工作面的推進,老頂初次來壓步距為22.49m,周期來壓步距為14.4m,凍土層將持續(xù)下沉,離層范圍會逐漸擴大,當開采范圍達到一定程度后多年凍土層會發(fā)生破斷并且整體下沉,易引起工作面頂板控制問題突出。研究結果對娘姆特煤礦的實際生產(chǎn)具有指導意義。
[Abstract]:The coal seam in the first mining area of Niangmute coal mine belongs to the large dip coal seam, which has not been mined at present. There is 20m-70m thick permafrost on the surface of the mining area, and no one has studied the problem of mining face pressure in the coal seam mining face under the permafrost. The particularity of permafrost determines the particularity of mining pressure law. The influence of permafrost on mine rock pressure is mainly reflected in the fact that the break of permafrost makes the working face the phenomenon of rock pressure impact, thus posing a serious threat to the personal safety of the underground production personnel. Therefore, it is urgent to study the law of mine pressure in the first fully mechanized caving face of Niangmte Coal Mine. In this paper, the relationship between physical and mechanical properties of permafrost and temperature is studied, and the law of overlying rock migration and stress distribution in the first mining face of Niangm is analyzed by means of experiments. The results show that the temperature distribution of permafrost is affected by burial depth, and the temperature of thawing layer is influenced by seasonal temperature, and the temperature distribution of frozen soil tends to be consistent with the depth of permafrost in summer and winter. The temperature gradient of permafrost is about 0.1 鈩，

本文編號：2334836