榆神矿区侏罗—白垩系含水介质结构与采动破坏特征

发布时间：2018-04-16 13:16

本文选题：侏罗-白垩系 + 介质结构　；参考：《中国矿业大学》2017年硕士论文

【摘要】：陕北榆神矿区是榆神府侏罗纪煤田的精华部分,是我国最主要的特大型煤炭生产基地之一。侏罗-白垩系是我国西部富煤区的主要富煤地层,其与东部华北型煤田的石炭-二叠系存在着巨大的不同,具有独特的含水介质结构与采动破坏特征,这对矿井充水条件评价影响重大。本论文以榆神矿区地质背景为基础,利用实地岩样进行X射线衍射、扫描电镜、压汞试验等试验,结合研究区域宏观地质沉积环境及其演化,从矿物成分、孔隙结构、岩石力学特性方面分析了榆神矿区侏罗-白垩系结构与微观孔隙结构特征;其次选取榆树湾煤矿为原型地质条件,通过室内相似材料模拟和数值模拟手段,研究了特殊结构覆岩的破坏特征和导水裂隙带发育规律;然后通过分析侏罗-白垩系的展布规律和地层结构特征,根据导裂带破坏范围和可能影响到的含水层的介质结构等条件,分析了侏罗-白垩系特殊的介质结构和采动破坏特征对矿井充水的水文地质意义,并探讨了该区煤矿保水采煤的典型工程实践案例。本文研究的主要内容及成果如下:(1)榆神矿区侏罗-白垩系经历了复杂特殊的成岩环境和短暂的沉积演化过程,利用X射线衍射、扫描电镜和压汞试验分析,得出了侏罗-白垩系强度低、胶结弱、孔隙度高、渗透性好等微观孔隙结构特征,如直罗组岩样孔隙度15.53%,远高于我国东部石炭-二叠系砂岩1.1~2%的孔隙度。(2)采用相似材料模拟实验和数值模拟手段对榆树湾煤矿覆岩破坏特征和导裂带演化规律进行了研究,模拟开采2-2煤5m上分层,覆岩变形破坏发育缓慢,最终形成跨度较大的离层空间和“平拱”形态,发育高度为55m和49m,模拟值与经验公式计算值存在差异,显示出了侏罗-白垩系覆岩破坏的特殊性。(3)该区侏罗-白垩系的宏观分布规律控制了地下水的总体向东南方汇集的径流特征,根据岩性岩相与分布特征概化为三个含水岩组,直接充水水源主要侏罗-白垩系的基岩承压水;主要导水通道为顶板基岩冒落裂隙带,其次原生结构面裂隙等充水通道;以锦界煤矿为例,分析了典型突水矿井的充水强度因素以及裂隙闭合对充水的影响。(4)榆树湾煤矿上分层采煤,实际导裂带未破坏到潜水含水层,证实了试验模拟得出的覆岩破坏规律,为该区域类似矿井地质条件下的保水采煤实践积累了经验,为保水开采的开拓提供了思路。
[Abstract]:Yushen mining area in northern Shaanxi is the essence of Jurassic coal field of Yushenfu and one of the most important coal production bases in China.Jurassic-Cretaceous is the main coal-rich stratum in the coal-rich area of western China. It is different from the Carboniferous Permian system in the North China type coal field in the east of China, and has unique water-bearing medium structure and mining failure characteristics.This has a great impact on the evaluation of mine water filling conditions.On the basis of geological background of Yushen mining area, this paper carries out X-ray diffraction, scanning electron microscope, mercury injection test and so on by using field rock samples, combined with the study of the regional macro-geological sedimentary environment and its evolution, from the mineral composition, pore structure, and so on.The characteristics of Jurassic-Cretaceous structure and micro-pore structure in Yushen mining area are analyzed in terms of rock mechanical properties. Secondly, the Yushhuwan coal mine is selected as the prototype geological condition, and the indoor similar material simulation and numerical simulation are carried out.In this paper, the failure characteristics of overburden rock with special structure and the development law of water-conducting fissure zone are studied, and the distribution law and stratigraphic structure characteristics of Jurassic-Cretaceous system are analyzed.According to the damage range of the fracture zone and the medium structure of the aquifer, the hydrogeological significance of the special medium structure of Jurassic-Cretaceous system and the characteristics of the mining failure to the mine water filling are analyzed.The typical engineering practice case of coal mining with water conservation in this area is also discussed.The main contents and results of this paper are as follows: (1) Jurassic-Cretaceous in Yushen mine area has undergone complex and special diagenetic environment and brief sedimentary evolution process.The characteristics of micro-pore structure, such as low strength of Jurassic-Cretaceous system, weak cementation, high porosity and good permeability, are obtained.For example, the porosity of rock samples of Zhiluo formation is 15.53, which is much higher than the porosity of 1.1% of Carboniferous-Permian sandstone in the east of China. The failure characteristics of overburden rock and the evolution law of fracture guide zone in Yushhuwan Coal Mine are studied by means of similar material simulation experiment and numerical simulation.In simulated mining of 2-2 coal, the deformation and failure of overburden is slow, and the formation of "flat arch" with large span is formed. The height of development is 55m and 49m, and there is difference between the simulated value and the calculated value of empirical formula.It is shown that the characteristics of Jurassic-Cretaceous overburden failure are special.) the macroscopic distribution law of Jurassic-Cretaceous in this area controls the runoff characteristics of groundwater aggregating to the southeast. According to the lithologic lithofacies and distribution characteristics, it is generalized into three water-bearing rock formations.The water source of direct water filling is mainly Jurassic-Cretaceous bedrock confined water, the main channel is roof bedrock caving fissure zone, and the primary structure plane fissure is the other water filling channel; taking Jinjie coal mine as an example,This paper analyzes the factors of water filling intensity of typical water-inrush mine and the influence of fissure closure on water-filling. 4) the stratified coal mining in Yushhuwan coal mine is not destroyed by the actual crack guide zone, which proves the failure law of overburden rock obtained by test simulation.It has accumulated experience for the practice of water-retaining coal mining under similar geological conditions in this area, and provided some ideas for the exploitation of water-retaining mining.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD163.1

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