急倾斜煤层层间岩柱动力失稳致灾机制研究

发布时间：2018-02-12 16:07

本文关键词： 急倾斜煤层层间岩柱应力撬转效应诱灾倾向预测灾害防治　出处：《西安科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：急倾斜煤层赋存环境特殊,动力灾害频发。乌东煤矿急倾斜煤层层间夹持巨厚岩柱,岩柱破裂、失稳是诱发开采空间动力灾害事故的力源之一,岩柱失稳诱发动灾事故严重制约矿井安全生产。急倾斜赋存条件与高阶段水平分段开采方法决定了岩柱失稳机制与诱灾过程具有复杂性,因而开展急倾斜煤层层间岩柱动力失稳致灾研究具有重要意义。论文以乌东煤矿南采区急倾斜煤层层间巨厚岩柱为研究对象,通过地质条件调查,分析动力灾害影响因素;基于急倾斜煤岩体结构特征构建力学模型,揭示岩柱失稳致灾机制;借助FLAC3D数值计算软件,验证力学模型的合理性;运用声发射、地质雷达等监测手段,预测岩柱动力失稳诱灾倾向性区域,提出动力灾害防治措施,现场实施并评估防治效果。地质调查表明硬底-硬煤-硬顶条件下煤层、顶板厚度大,层间岩柱(顶、底板)坚固完整,为动力灾害的发生提供了基础条件,乌东煤矿南采区开采深度350m,在当前开采条件下达到了动力灾害频发临界开采深度;基于急倾斜煤岩结构,构建了急倾斜岩柱应力撬转效应(stress leverage rotation effect,SLRE)力学模型,应力撬转作用为动力灾害的发生提供了力源条件;数值计算表明岩柱基座出现活化,运动趋势显著,岩柱变形矢量特征与岩柱撬转运动趋势相吻合;分析现场监测数据,煤岩体能量释放总体呈现平缓-升高-平缓‖变化特征,并显现出一定的周期性(23-30天),岩柱失稳致灾过程可分为扰动破裂、应力挤压、断裂失稳和应力重构4个阶段;结合监测结果与岩柱失稳致灾机制,考虑岩性、开采等动力灾害孕育条件,预测了当前开采条件下岩柱动力失稳诱灾倾向区域,分别位于B1-2煤层+500m~+510m区域开采煤体、B3-6煤层+475m~+485m区域岩柱侧煤体;依据预测结果,提出煤层注水、岩柱注水、岩柱深孔爆破等动力灾害防治措施并确定相关参数,经现场实施与效果评价,动力灾害防治措施科学有效。研究结果对相似开采条件下动力灾害的防治具有借鉴意义。
[Abstract]:The occurrence environment of steeply inclined coal seam is special and the dynamic disasters occur frequently. The rock column is broken and the instability is one of the sources of inducing the spatial dynamic disaster accident in Wudong Coal Mine, which is held between the layers of the steeply inclined coal seam, and the rock column is broken. Rock column instability induced dynamic disaster seriously restricts the safety of mine production. The occurrence condition of steep slope and the high level mining method determine the complexity of rock column instability mechanism and disaster induction process. Therefore, it is of great significance to study the dynamic instability of rock column in steep seam. This paper takes the interlayer thick rock column of steep inclined coal seam in the south mining area of Wudong Coal Mine as the research object, and analyzes the influencing factors of dynamic disaster through the investigation of geological conditions. Based on the structural characteristics of steeply inclined coal and rock mass, the mechanical model is constructed to reveal the mechanism of rock column instability, the rationality of the mechanical model is verified by means of FLAC3D numerical calculation software, and the monitoring means such as acoustic emission and geological radar are used. Prediction of dynamic instability induced disaster prone area of rock column, put forward dynamic disaster prevention measures, field implementation and evaluation of the prevention and control effect. Geological investigation shows that the coal seam under the condition of hard bottom, hard coal and hard roof, the roof thickness is large, and the interlayer rock column (top). The bottom slab) is solid and complete, which provides the basic conditions for the occurrence of dynamic disasters. The mining depth in the south mining area of Wudong Coal Mine is 350 m, and under the current mining conditions, the critical mining depth of frequent dynamic disasters has been reached; based on the structure of steeply inclined coal and rock, The stress leverage rotation effect SLREE (stress leverage rotation effect SLREE) mechanical model of steeply inclined rock column is constructed. The stress prying effect provides the force source for the occurrence of the dynamic disaster, and the numerical calculation shows that the rock column foundation is activated and the movement trend is obvious. The characteristics of rock column deformation vector are consistent with the movement trend of rock pillar prying, and the energy release of coal and rock mass is generally characterized by flat-level-heaving and flattening variation by analyzing the field monitoring data. The process of rock column instability can be divided into four stages: disturbance rupture, stress compression, fracture instability and stress reconstruction. Under the condition of mining and other dynamic disasters, the tendency of rock pillar dynamic instability induced disaster is predicted, which is located in 500m ~ 510m area of B1-2 coal seam, mining coal body in 475m ~ 485m area of coal seam B3-6, according to the prediction results, The measures of preventing and controlling dynamic disasters such as coal seam water injection, rock column water injection and rock pillar deep hole blasting are put forward, and the relevant parameters are determined, which are carried out on the spot and evaluated for the effect. The results can be used for reference in the prevention and treatment of dynamic disasters under similar mining conditions.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD823.213

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