【摘要】：我國西北部地區(qū)巨厚煤層分布較廣,煤層開采后覆巖移動及地表下沉規(guī)律與一般厚度煤層的相比具有很大的差異性。論文針對鄂爾多斯地區(qū)煤層厚度大,地表多為黃土層所覆蓋等特殊地質條件,結合不連溝煤礦典型工作面采后地表下沉現(xiàn)象,綜合運用現(xiàn)場踏勘、理論分析、相似材料試驗和數(shù)值模擬等方法,對該地區(qū)巨厚煤層開采覆巖移動及地表下沉特征進行了系統(tǒng)研究。論文主要取得了以下研究成果:(1)結合不連溝煤礦覆巖結構,運用關鍵層理論,得到了不連溝煤礦6#煤層頂板覆巖中存在的關鍵層數(shù)量、初次破斷及周期破斷規(guī)律,并結合失穩(wěn)條件,給出了關鍵層破斷巖塊形成結構的失穩(wěn)形式。(2)分析巨厚煤層開采特點,建立了高位短懸臂梁-臺階巖梁的力學模型,推導出了該結構不發(fā)生滑動失穩(wěn)所需支撐力的表達式,帶入相關參數(shù)后得出,巨厚煤層大采高采場頂板需要更大的支護強度。(3)區(qū)域內巨厚煤層采后覆巖只存在兩帶即垮落帶和裂縫帶;通過現(xiàn)場觀測、數(shù)值模擬及相似材料模擬得出關鍵層對導裂帶發(fā)育、地表沉陷等起控制作用,采后在工作面兩側及切眼一側覆巖破斷后沿垮落角方向的裂隙明顯,裂縫寬度大,薄基巖礦區(qū)導裂帶包絡線呈正梯形。
[Abstract]:Thick coal seams are widely distributed in Northwest China, and the laws of overlying strata movement and surface subsidence after coal mining are quite different from those of common thick coal seams. The subsidence phenomenon is studied systematically by using the methods of field investigation, theoretical analysis, similar material test and numerical simulation. The main research results are as follows: (1) Combining with the overburden structure of Duangou Coal Mine, the key stratum theory is applied to get the Duangou Coal Mine. 6 # coal seam roof overburden in the number of key strata, the first break and periodic break law, combined with instability conditions, the formation of key strata broken rock block structure of the instability form. (2) analysis of the mining characteristics of thick coal seam, the establishment of a high-level short cantilever beam-bench rock beam mechanical model, derived the structure of the sliding instability. The expression of supporting force is introduced, and it is concluded that the roof of large mining height stope in huge thick seam needs more supporting strength. (3) There are only two zones of collapse zone and fracture zone in the overlying strata of huge thick seam after mining. Through field observation, numerical simulation and similar material simulation, it is concluded that the key strata control the development of leading fracture zone and surface subsidence. After mining, the cracks along the caving angle direction are obvious on both sides of the working face and one side of the cut hole, and the width of the cracks is large, and the envelope of the fracture conduction zone in the thin bedrock mining area is normal trapezoidal.
【學位授予單位】：中國礦業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TD325

【參考文獻】

相關期刊論文 前1條

1 錢鳴高，繆協(xié)興;采場上覆巖層結構的形態(tài)與受力分析[J];巖石力學與工程學報;1995年02期

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本文編號：2229626