【作者】 乔伟；

【导师】 李文平；

【作者基本信息】 中国矿业大学 ， 地质工程， 2011， 博士

【摘要】 我国华北东部主要煤矿目前开采深度达到600m左右,且以大约12m/a的速度向深部延伸。作为华北型煤矿煤系基底的奥陶系岩溶含水层是影响石炭纪煤层开采的主要充水水源。由于矿井开采向深部延伸,面临深部高承压甚至是超高承压奥灰水威胁,研究深部裂隙岩溶水运移、富水规律,科学评价其对煤层开采的突水危险性,是确保深部煤层安全开采的重大基础性研究课题。论文以兖州煤田兴隆庄矿井和东滩矿井为研究区,通过地面抽水试验、井下群孔放水试验、孔隙-裂隙率测试以及水化学场和水动力场模拟计算等手段揭示了研究区深部奥陶系裂隙岩溶含水层的富水特征,并提出适合深部开采的底板突水危险性评价方法。取得以下成果:(1)对华北煤矿区奥陶系沉积岩相、古地理和岩溶发育特征进行了阐述,明确了奥陶系岩溶是在古岩溶的基础上继承和发展的,深部岩溶是在古浅部岩溶下降后继续发展的结果,且华北煤矿区深部奥陶系岩溶发育形态总体以孔隙、裂隙岩溶为主。(2)通过分析华北典型煤矿区底板岩溶水涌(突)水特征,并在统计分析焦作、淄博和肥城矿区17个矿井212次底板突水实例的基础上,总结提出了底板岩溶突水水量和突水概率随着开采深度增加具有“递减型”、“增减型”(先递增后递减)趋势的规律。(3)从岩性、构造、水流场和水化学场等方面研究了深部岩溶发育的影响因素。可溶岩的岩性作为物质基础,不会随着埋深位置的深浅而发生岩石化学成分改变。构造条件是影响深部岩溶含水层富水性的重要因素,从褶皱构造形成的地质力学过程分析了褶皱构造核部位置往往是深部岩溶富水的部位的特征。水化学场和水流场对深部岩溶的控制作用主要是由构造条件决定的。(4)在系统分析区域奥陶系岩溶含水层水文地质特征基础上,采用化学热力学方法对研究区岩溶发育趋势进行了判别。基于水化学资料,用主成分分析方法研究了奥陶系深部岩溶发育的主控因素。使用水化学方法和构造控水机理,划分了研究区的水动力分区。基于研究区地应力测试分析,研究了地应力与裂隙岩溶富水性的关系,并得到了相关公式。探讨了深部裂隙岩溶含水介质溶蚀裂隙扩展的机制,认为地应力值的变化(埋深的增加)影响了裂隙的张开度,而裂隙的张开度是影响深部岩溶裂隙溶蚀扩展的重要因素。(5)通过井下群孔放水试验和地面抽水试验,分析放水试验期间水位和水化学成分变化,建立了研究区奥陶系顶部裂隙岩溶含水层水文地质(包括水文化学)数值模型,并对地下水流场、水化学性变化进行了模拟;揭示了研究区奥陶系裂隙岩溶含水层的流场、富水性和水化学特征。对研究区深部岩溶化作用现状进行了分析。(6)在大量突水实例统计分析的基础上,对突水危险性与突水系数、充水含水层富水性之间的关系进行深入研究,得到了一些规律性的认识;提出了底板突水危险性预测评价Ts-q法,弥补了传统突水系数法评价突水危险性未考虑充水含水层(水源)富水性大小(钻孔单位涌水量q)的不足,常识性突破了深部“高承压—弱富水”水文地质条件因突水系数超限而不能开采的瓶颈;且方法简单实用,便于生产单位普遍推广应用;探索了我国矿山进入深部开采水害预测评价新的理论依据、并在研究区进行了应用。该论文有图134幅,表41个,参考文献255篇。更多还原

【Abstract】 The present mining depth reaches about 600m and inreases 12m per year to deep part in key coal mines of eastern North China. Being the basement of coal measure strata in North China coal mine, the Ordovician fracture-karst aquifer is the baleful source of water for exploiting the Carboniferous coal bed. The coal mines that the exploitation transfers into the deep stratum will be threaten by the deep high or superhigh pressure confined water from Ordovician. Mastering the water abundance and migration regularity of deep fracture-karst aquifer is one of the basal and prerequisite works for emancipating deep coal resources and ensuring safety for exploiting the deep coal bed.The paper takesⅠexploration areas for lower-group coal bed in Xinglongzhuang and Dongtan coal mine as the researched area. The water abundance characteristic of deep Ordovician fracture-karst aquifer is exposed by the ground pumping test, dewatering test in the pit, porosity and cranny ratio testing, hydrochemical field and hydraulic field analog computation. And the method which is suitable for the deep exploitation and used for evaluating criticality of water inrush from coal floor is put forward. The main results are as follows:(1) The sedimentary facies, paleogeography and karst characteristic of the Ordovician in coal mines of eastern North China is expounded. And the modern deep karst of the Ordovician is inheriting and developing on basis of palaeokarst and the declining shallow karst. And the development form of deep Ordovician karst in coal mines of eastern North China is pore and fracture.(2) The regularity of water inrush and water burst from the karst aquifer below the coal bed is analysed in division coal field of of eastern North China. And on basis of censusing and analysing 212 examples of water inrush from floor from 17 coal mines in Jiaozuo, Zibo and Feicheng mining area, the regularity of water yield and water inrush probability decreasing following the diminishing elevation and from rising to decreasing following the diminishing elevation is put forward.(3) Controlled factors of deep karst development have been studied from three aspects, including lithology, geologic structure, hydraulic field and hychemical field. Control action will not change with depth for soluble rock, as a material base, will not change its chemical composition with depth changing. The geologic structure is the main factor effecting the water abundance of deep karst aquifer. The form mechanism of folded structure is analysed and the folded structure core is always the place of water abundance. The control action of hydraulic field and hychemical field has relation to geology structure.(4) The chemical thermodynamics method is used for distinguishing the trend of karst development in researched area on basis of systematicly analyzing hydrogeological characteristic of the Ordovician karst aquifer. The principal component analysis method is used to study the master control of the Ordovician deep karst development. The hydraulic subareas have been divided using the hychemical method and the mechanism of geology structure water mimicry.The relation between geo-stress and water abundance of fracture-karst is studied on basis of geo-stress test in researched area, and the relation formula has been obtained. The dissolution fracture expanding mechanism of deep fracture-karst aquifer is discussed. The changing geo-stress(increased burial depth) effects the fracture aperture. And the fracture aperture is the main factor for effecting the fracture expanding in deep karst.(5) The flow field and water abundance characteristic of Ordovician fracture-karst aquifer in researched area is exposed by the method of dewatering test in the pit, ground pumping test and analyzing the change of water level and water chemistry composition. A hydrogeological conceptual model of the Ordovician fracture-karst aquifer in researched area has been set up, and the groundwater flow field has been analysed. The hydrochemical analog computation has been carried out for Ordovician fracture-karst aquifer in researched area. Above all, the karstification of deep karst in researched area can be simulated.(6) Based on the water inrush coefficient Ts, the unit inflow q, an index reflecting water bearing of the aquifer, is introduced. Based on statistical analysis of a large number of examples of water inrush, the relationships between water inrush potential, water inrush coefficient, and the water-enriched properties of aquifer are further researched. The achieved laws of water inrush are discussed. And a new method for evaluating risk of floor water inrush is put forward. The method of water inrush coefficient-unit inflow method can be a supplement for evaluating water inrush coefficients. The achieved results can be provided for evaluating water inrush risk of floor in deep mining of some mining areas, in which the water-enriched properties of aquifer are not obvious but water inrush coefficient is larger. And the coefficient-unit inflow method is applied for evaluating water inrush risk from floor in deep mining of the researched area on basis of analyzing the water abundance regularity of Ordovician in researched area using the dydraulic and dychemical method. The water inflow has been calculated. Ultimately, relevant preventive measures can be drawn up. The paper has 134 maps, 41 tables, 255 refernces.更多还原