【摘要】：頂板淋水事故易于引發(fā)大傾角軟煤綜放面“支架—圍巖”系統(tǒng)失穩(wěn)。針對(duì)長(zhǎng)山子煤礦1125大傾角軟煤綜放面開(kāi)采初期遭遇頂板淋水后引發(fā)的中下部支架傾倒事故,通過(guò)分析工作面覆巖結(jié)構(gòu)及水文地質(zhì)資料,確定了工作面頂板淋水原因;運(yùn)用理論分析和建立物理力學(xué)模型,闡明了頂板淋水對(duì)支架穩(wěn)定性和頂?shù)装宸�(wěn)定性影響,研究了淋水?dāng)_動(dòng)下頂板巖層的破壞機(jī)理及特征;根據(jù)煤層賦存條件,采用FLAC3D建立流固耦合數(shù)值模型研究了大傾角軟煤綜放面在頂板水作用下的圍巖應(yīng)力、位移及塑性破壞分布規(guī)律;最后制定了支架穩(wěn)固方案及傾倒支架安全扶穩(wěn)方案并付諸實(shí)施。具體研究結(jié)果如下:(1)1125工作面頂板淋水來(lái)源為其頂板侏羅紀(jì)新河組砂礫巖含水層孔隙裂隙水,淋水原因?yàn)檐浫蹴敯鍘r層受開(kāi)采擾動(dòng)影響產(chǎn)生由下向上擴(kuò)展的縱向裂隙,裂隙貫通至頂板砂礫巖含水層時(shí)形成導(dǎo)水通道,繼而致使局部集聚的頂板水下淋。(2)頂板淋水對(duì)支架穩(wěn)定性的擾動(dòng)主要表現(xiàn)為淋水侵蝕軟弱破碎頂板造成頂板抽冒;底板受淋水浸泡軟化變形致使支架底座下陷,二者綜合導(dǎo)致支架大范圍空頂。支架底座間的浮煤與淋水作用形成煤泥,造成工作面底板濕滑,加劇了支架向下滑移的趨勢(shì)。(3)頂板淋水?dāng)_動(dòng)下1125工作面頂板巖層破壞機(jī)理為:采動(dòng)裂隙隨著工作面的推進(jìn)不斷發(fā)育在頂板巖層形成松動(dòng)帶,頂板淋水削弱了頂板巖層顆粒間的黏聚力,降低了頂板巖層的抗剪切強(qiáng)度,溶解了頂板巖層部分膠結(jié)物,泥化了破碎頂煤,降低了工作面頂板強(qiáng)度及穩(wěn)定性。頂板水對(duì)松動(dòng)帶裂隙施加的裂隙水壓力使其發(fā)生垂直變形、切向變形以及位移,打破了頂板巖層原有平衡,最終導(dǎo)致其出現(xiàn)貫穿性破壞面并引發(fā)失穩(wěn)。(4)FLAC3D數(shù)值模擬結(jié)果表明,頂板水?dāng)_動(dòng)下其頂板垂直應(yīng)力呈不均勻無(wú)規(guī)則分布,應(yīng)力擾動(dòng)范圍較大,頂板變形程度及頂板塑性破壞區(qū)較無(wú)水干涉條件下均顯著增大,增加了大傾角軟煤綜放面頂板巖層失穩(wěn)趨勢(shì)。(5)支架穩(wěn)固方案和傾倒支架動(dòng)態(tài)扶穩(wěn)方案有效控制了工作面水患,扶穩(wěn)了受淋水影響傾倒的支架,確保了大傾角軟煤綜放面“支架—圍巖”系統(tǒng)的穩(wěn)定性。本論文研究結(jié)果對(duì)于解決水文條件相對(duì)簡(jiǎn)單的大傾角軟煤綜放面突發(fā)頂板淋水事故后引發(fā)“支架—圍巖”系統(tǒng)失穩(wěn)及推進(jìn)緩慢問(wèn)題具有借鑒意義,所確定的支架穩(wěn)固方案及傾倒支架扶穩(wěn)方案為大傾角軟煤綜放面安全通過(guò)淋水區(qū)域提供了保障。
[Abstract]:Roof flooding accidents are apt to lead to instability of "support-surrounding rock" system in fully mechanized coal caving face with large dip angle. In view of the caving accident of the middle and lower part of the fully mechanized caving face of Changshanzi coal mine during the initial stage of mining, the overburden structure and hydrogeological data of the working face are analyzed, and the reason of roof flooding is determined. Based on the theoretical analysis and the establishment of physical and mechanical models, the effects of roof water on the stability of the support and the roof and floor are expounded, and the failure mechanism and characteristics of the roof strata under the disturbance of water flooding are studied. According to the condition of coal seam occurrence, the numerical model of fluid-solid coupling is established by FLAC3D to study the distribution of surrounding rock stress, displacement and plastic failure of fully mechanized caving face with large dip angle under the action of roof water. Finally, the scheme of support stability and the safety support scheme of toppling bracket are worked out and put into practice. The concrete results are as follows: (1) the source of roof water in 1125 working face is pore fissure water of sandy gravel aquifer of Xinhe formation in the roof of Jurassic, which is caused by the influence of mining disturbance on weak roof strata, which is caused by the vertical fracture extending from the bottom up. When the fissure passes through to the sand and gravel aquifer of the roof, a water conduction channel is formed, which leads to the local accumulated roof underwater leaching. (2) the disturbance of roof water to the stability of the support is mainly caused by water erosion and weak broken roof, which results in the roof caving; The bottom plate is softened and deformed by drenching water, which results in the collapse of the base of the support, and the combination of the two causes the large-range hollow roof of the support. The floating coal between the base of the support and the dripping water form the coal slime, which causes the floor of the working face to be wet and slippery. (3) under the roof water disturbance, the failure mechanism of roof strata in 1125 working face is as follows: the mining fissure develops continuously in the loose zone of roof rock with the advance of working face. Roof flooding weakens the cohesion between roof rock particles, reduces the shear strength of roof rock, dissolves some cementing matter of roof rock, muddies broken top coal, and reduces the strength and stability of working face roof. The crack water pressure exerted by roof water on the crack in the loose zone causes the vertical deformation, tangential deformation and displacement, thus breaking the original balance of the roof rock layer. The results of FLAC3D numerical simulation show that the vertical stress of the roof is uneven and irregular, and the range of the stress disturbance is large. The degree of roof deformation and the plastic failure zone of roof are significantly increased compared with those under the condition of no water interference. The trend of instability of roof strata of soft coal caving face with large dip angle is increased. (5) the support stabilization scheme and the dynamic support scheme can effectively control the flood hazard of the working face and stabilize the support which is affected by the pouring water. It ensures the stability of the support-surrounding rock system of the fully mechanized top coal caving face with large dip angle. The results of this paper can be used for reference to solve the problem of "support surrounding rock" system instability and slow advance caused by sudden roof sprinkling accident in soft coal caving face with large dip angle, which is relatively simple in hydrological condition. The fixed support scheme and the toppling support scheme provide a guarantee for the safety of fully mechanized top-coal caving face with large dip angle through the flooded area.
【學(xué)位授予單位】：西安科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TD355.4

【參考文獻(xiàn)】

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本文編號(hào)：2380601