山西霍宝干河煤矿煤层底板突水评价与预测预报研究

发布时间：2018-05-31 22:51

本文选题：矿压破坏带预测 + 底板突水评价　；参考：《中国矿业大学(北京)》2017年博士论文

【摘要】：煤层底板水害因其剧烈的致灾性引起了国内外广泛研究与关注。近年来,作为山西焦煤霍州煤电集团主力生产矿井之一的霍宝干河煤矿,其主采煤层(上组2#和下组10#煤层)开采正受到煤层底板承压含水层水的巨大威胁。针对以上问题,为控制煤层底板承压含水层水对该矿主采煤层开采构成的威胁,文中综合运用水文地质钻探、抽水试验、水文测井、岩与水试样测试、煤层底板破坏理论计算和有限元RFPA-2D数值模拟分析、“脆弱性指数法”和“五图双系数法”煤层底板突水评价等技术方法,对该矿2#和10#主采煤层在其底板石炭系太原群灰岩和奥陶系灰岩含水层水源威胁下的底板突水危险性进行了评价区划,并与实际开采揭露的水文地质条件进行了对比与完善,优选了适合相似地质条件下相关问题的综合评价技术与方法,并提出了针对具体评价结果和煤层回采实际揭露水文地质条件的煤层底板水害评价方法与防控措施,为保障矿山的安全开采提供了重要技术支持。通过以上相关研究,其主要成果如下:⑴通过水文地质钻探、抽水试验、水文测井和岩、水试样分析测试和相关理论计算等工作方法与技术手段,查明了矿井边界断层性质及其对矿井开采的威胁,预测了未来开采矿井涌水量,查明了石炭系太原群灰岩(K2灰岩)和奥陶系灰岩的厚度、岩性和富水性等特征,即:K2灰岩属弱富水性含水层,而奥陶系灰岩属强富水性含水层;查明了主采煤层(上组2#煤和下组10#煤,下同)与其底板主要承压含水层的隔水层厚度、岩性、岩石力学指标和阻水性能等特征,查明了主要煤层底板各主要承压含水层之间的水力联系,即奥灰含水层在局部通过垂向构造补给K2灰岩含水层,是K2灰岩含水层的主要补给来源。⑵运用有限元RFPA-2D软件对上组2号煤开采造成的底板矿压破坏范围进行了数值模拟分析,并将其模拟结果与理论计算及周边矿井原位实测经验值及成果进行了对比分析。即:在考虑随工作面长度推进和工作面不同采宽时的该煤层底板矿压破坏深度为约14m,小于理论公式及现场实测成果的22~25m,为确保后续评价成果安全性,将经理论公式计算和周边矿井原位实测成果作为后续评价主要依据。该煤层开采底板矿压破坏深度的综合评价为后续煤层底板突水危险性区划评价提供了技术支持。⑶对研究区主采煤层的底板突水脆弱性采用“脆弱性指数法”进行了评价区划。结果表明:(1)在干河矿区范围内,2#号煤层底板K2灰岩含水层突水可能性从南向北呈递增态势,而在断层和褶皱等构造分布区域则多处于脆弱和较脆弱区;(2)干河煤矿10#煤层开采时底板奥灰突水可能性整体较大,即:其相对安全区主要分布在矿井东南部,较脆弱区则集中在矿井中北部,而脆弱区则主要集中在矿井构造较发育地带的矿井北部和矿井其他部位。⑷对研究区主采煤层的底板突水危险性采用“五图双系数法”进行了评价和区划。结果表明:(1)该矿2#煤层开采时底板K2灰岩含水层在矿井中北部易形成非直通式突水,而因奥灰含水层形成的突水可能性较小,危险区仅存在于矿井北部小部分区域;(2)该矿10#煤层开采时底板形成奥灰含水层直通式突水的区域主要集中在井田西部,而形成非直通式突水的区域主要集中在井田中东部。⑸综合上述两种方法所得评价结果并与开采揭露水文地质条件对比,可以看出:(1)运用“脆弱性指数法”进行底板突水危险性评价时,考虑主控因素比较多,体现了地质现象的逐渐变化特征,而“五图双系数”进行底板突水危险性评价,考虑的因素少,没有明显的过渡区;(2)“五图双系数法”没有考虑构造对煤层底板突水评价的影响致使其评价结果安全性偏低;(3)底板突水是一个非线性的多因素的突发性比较强的过程。“脆弱性指数法”更好地反映了煤层底板突水非线性、多因素和突发性特征,而单纯考虑底板隔水层与水头因素,不能更好地反映实际情况;(4)“五图双系数法”评价结果较为保守,导致大量煤炭资源浪费,而脆弱性指数法则能更大地解放煤炭资源,增加经济效益,缓解能源紧张。综上所述,文中将基于“脆弱性指数法”的评价结果作为其最终依据。⑹提出了基于上述“脆弱性指数法”评价结果和经开采实践验证的主采煤层底板突水防控技术方法。即:(1)对于评价区划结果的相对安全区和较安全区,应采取在生产中时刻关注回采工作面情况、涌水量变化和太灰水位变化,发现异常,及时上报的应对措施。(2)对于评价区划结果的过渡区,除采取在相对安全区和较安全区的防控措施在,还应采用含水层改造和隔水层加固、注浆措施改造含水层或加固隔水层,进一步提高隔水层强度。(3)对于评价区划结果的较脆弱区,应主要采取以下措施,即:在回采过程中进行超前探水;利用物探、钻探等综合勘探手段,查明隔水层薄弱地段、富水区段和潜在导水通道(断层、裂隙带);采用地球物理、钻探等手段,查明回采工作面范围内煤层底板岩层的连续性与裂隙发育特征,确定裂隙发育地段,采取注浆改造措施改造含水层和加固隔水层,使其变为相对隔水层甚至隔水层,进一步提高开采安全性;在生产中疏降含水层水压至安全水压再进行回采作业,特别对于情况复杂地段,在巷道掘进过程中应进行超前探放水并酌情设立防水闸门。(4)对于评价区域结果的脆弱区,应采取以下主要防控措施:对隔水层厚度较薄区域,采取注浆加固隔水层方法,以确保隔水层强度满足水压破坏与安全开采要求,对于矿压破坏带下脆性岩厚度较小区域,亦可采取注浆加固,以确保隔水层强度;对于区域富水性较高区域,可疏水降压后进行开采;而对于水头压力较大采区,则需采取疏水降压方法,基于具体情况和现场经验,把承压含水层水头压力降到隔水层所能承受的安全水头压力范围内。(5)需要特别指出的是,对于断层、褶皱等构造分布区,因构造的存在破坏了隔水层连续性,因此当煤层回采揭露这些构造时,其可能会作为导水通道直接或间接把含水层承压水引入工作面进而造成严重后果。故主要应采取以下措施加以应对,即:首先,在煤层回采中对这些区域留设足够的隔水煤(岩)柱,严重的可采取两盘预注浆或局部疏水降压等措施处理;其次,在巷道掘进靠近这些构造分布区域时应进行超前探放水,利用物探、钻探等综合探查手段,查明构造具体产状和影响区域,同时利用其他手段探查构造富水性,再基于此采取超前探放水措施或预留煤柱进行水害防治,并酌情设立防水闸门实现分区隔离开采,以确保回采安全;最后,对工作面回采已揭露但未突水断层,须加强观测,严防滞后突水灾害发生。
[Abstract]:The water damage of coal seam floor has caused extensive research and concern at home and abroad because of its severe disaster. In recent years, as one of the main production mines of Shanxi coking coal Huozhou coal and electricity group coal mine, the main mining coal seam (upper group 2# and lower group 10# coal seam) is being threatened by the coal seam floor bearing aquifer water. In order to control the threat to the mining of the main coal seam under the confined aquifer of the coal seam floor, the hydrogeological drilling, pumping test, hydrologic logging, rock and water test, the theory calculation of coal seam floor failure and the finite element RFPA-2D numerical simulation analysis, the "brittle index method" and "five figure double coefficient method" of coal seam floor are used in this paper. The water inrush evaluation of the 2# and 10# main coal seam in the coal mine under the threat of the water source of the Carboniferous Taiyuan group limestone and the Ordovician limestone aquifers in the floor is evaluated and divided, and the hydrogeological conditions are compared and perfected with the actual mining, and the relevant problems suitable for similar geological conditions are optimized. The comprehensive evaluation techniques and methods are put forward, and the water damage evaluation method and control measures for the coal seam floor are put forward in view of the concrete evaluation results and the actual mining of the coal seam, so as to provide important technical support for the safety mining of the mine. Water test, hydrologic logging and rock, water sample analysis and correlation theory calculation and other work methods and technical means have been used to find out the fault properties of the mine boundary and the threat to mine mining, predict the water inflow of the mine in the future, and find out the thickness, lithology and water rich of the Carboniferous Taiyuan group limestone (K2 limestone) and Ordovician. The K2 limestone belongs to the weak water rich aquifer, and the Ordovician limestone is a strong water rich aquifer, and the thickness, lithology, rock mechanics index and water resistance property of the main coal seam (the upper group 2# coal and the lower group 10# coal, the lower part) and the main bearing aquifers of the floor are identified, and the main bearing aquifers of the main coal seam floor are found out. The hydraulic connection of the aquifer of the AUG ash aquifer is partially recharged by the vertical structure of the K2 limestone aquifer, which is the main source of recharge of the aquifers of the K2 limestone. (2) the numerical simulation analysis of the failure range of the bottom ore pressure caused by the mining of the upper group 2 coal was carried out by the finite element RFPA-2D software, and its simulation results and theoretical calculation and in the surrounding mine in situ are carried out. The measured experience value and the results are compared and analyzed. That is: the depth of rock pressure failure of the floor of the coal seam is about 14m in consideration of the length of the working face and the width of the working face. It is less than the 22~25m of the theoretical formula and the field measured results. In order to ensure the safety of the follow-up evaluation results, the theoretical formula will be calculated and the measured results in the surrounding mine are in situ. As a follow-up evaluation, the comprehensive evaluation of the failure depth of the floor mine pressure in the coal seam provides technical support for the follow-up evaluation of the water inrush hazard zoning of the coal seam floor. (3) the evaluation of the vulnerability of the water inrush from the floor of the main coal seam in the study area is evaluated by the "vulnerability index method". The results show that: (1) in the scope of the dry river mine area, The possibility of water inrush from the K2 limestone aquifer of the 2# coal seam floor is increasing from the south to the north, while in the tectonic distribution areas such as faults and folds in the fragile and more fragile areas, (2) the possibility of the floor soot water inrush in the mining of the 10# coal seam in the dry river coal mine is large, that is, the relative safety area is mainly distributed in the southeast of the mine, and the more fragile area is set. In the middle and north of the mine, the fragile area is mainly concentrated in the north of the mine and the other parts of the mine. (4) the "five figure double coefficient method" is used to evaluate and zoning the risk of water inrush from the floor of the main coal seam in the study area. The results show that: (1) the floor of the floor K2 limestone aquifer in the 2# coal seam of this mine is in the middle of the mine. It is easy to form non direct water inrush, but the possibility of water inrush formed by the orot aquifer is small, and the dangerous area is only in the small part of the northern part of the mine. (2) the area of the orot aquifer direct water inrush in the bottom of the coal seam is mainly concentrated in the west of the mine when the 10# coal seam is mined, and the area of the non direct water inrush is mainly concentrated in Ida Naka. By comparing the results obtained by the two methods mentioned above and compared with the extraction of hydrogeological conditions, we can see: (1) when the "vulnerability index method" is used to evaluate the risk of water inrush in the floor, the main factors are considered, and the gradual change of geological phenomena is reflected, while the "five map double coefficients" is used to carry out the risk of water inrush in the floor. There are few factors to consider, and there is no obvious transition zone. (2) the "five graph double coefficient method" does not consider the effect of structure on the evaluation of water inrush from coal seam floor, resulting in the low safety of the evaluation result. (3) the water inrush from the floor is a nonlinear and multi factor sudden and strong process. The "vulnerability index method" reflects the bottom of the coal seam better. The water inrush is nonlinear, multi factor and sudden characteristic, but simply considering the floor and water head factors can not better reflect the actual situation. (4) the results of the "five graph double coefficient method" are more conservative, resulting in a large amount of coal resources waste, and the vulnerability index rule can more liberate coal resources, increase economic benefits, alleviate the energy tight. On the basis of the evaluation results of the "vulnerability index method", the paper puts forward the technical methods of water inrush prevention and control in the floor of the main coal seam, which is based on the evaluation results of the "vulnerability index method" and the mining practice. That is (1) the relative safety zone and the safer zone for the results of the evaluation should be taken. During the production, we should pay attention to the situation of the mining face, the change of water gushing and the change of the water level, the discovery of abnormal and timely reporting measures. (2) in the transition zone of the evaluation of the results of the zoning, in addition to the prevention and control measures in the relative safety zone and the safer area, the aquifers and the aquifers should be used to reinforce the aquifers and the grouting measures should be used to reconstruct the aquifers. Or reinforce the aquifers to further improve the strength of the aquifers. (3) the following measures should be taken to evaluate the fragility of the results of the zoning, that is, to explore the water in the process of recovery, and to find out the weak sections of the aquifers, the water rich sections and the potential water guide channels (faults and fissure zones), and the use of earth objects. According to the method of drilling and drilling, the continuity and fracture development characteristics of the coal seam floor in the mining face range are ascertained, the zone of fracture development is determined, the aquifers and the aquifers are strengthened by grouting transformation measures to make it become relative aquifers and even the aquifers to further improve the safety of the mining, and the water pressure of the aquifers in the production will be reduced to the safety. All water pressure will be carried out again, especially for complex areas, in the course of roadway driving, water and water proof gate should be set ahead. (4) the following main prevention and control measures should be taken to evaluate the fragile zone of regional results: the method of grouting and reinforcement of the aquifers should be taken to ensure the strong septum to ensure the strength of the aquifers. In order to meet the requirements of water pressure damage and safety mining, the grouting reinforcement can be adopted to ensure the strength of the aquifers for the lower brittle rock thickness area under the ore pressure failure zone, and to ensure the strength of the aquifers. Field experience, the pressure of the water head of the bearing aquifer is reduced to the safe water head pressure that the aquifers can bear. (5) it should be particularly pointed out that the tectonic distribution areas, such as faults and folds, have destroyed the continuity of the aquifers because of the existence of the structure, so when the coal seam is recovered to expose the structures, it may be directly or indirectly as the channel guide. It is necessary to take the following measures to bring the bearing water in the aquifer into the working surface. Therefore, the following measures should be taken to deal with it, that is, first, enough water separated coal (rock) columns are left in the coal seam mining, and two plates pregrouting or local hydrophobic depressurization can be taken seriously; secondly, the distribution of these structures is close to the distribution of these structures in the tunnel. In the area, we should go ahead and explore the water, use geophysical prospecting, drilling and other comprehensive exploration means to find out the concrete production and influence areas, and use other means to explore the structure rich water. Finally, it is necessary to strengthen observation and prevent the occurrence of delayed water inrush disaster.
【学位授予单位】：中国矿业大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TD745.2

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