Height prediction of water flowing fractured zones based on BP artificial neural network

Factures caused by deformation and destruction of bedrocks over coal seams can easily lead to water flooding(inrush)in mines,a threat to safety production.Fractures with high hydraulic conductivity are good watercourses as well as passages for inrush in mines and tunnels.An accurate height prediction of water flowing fractured zones is a key issue in today's mine water prevention and control.The theory of leveraging BP artificial neural network in height prediction of water flowing fractured zones is analysed and applied in Qianjiaying Mine as an example in this paper.Per the comparison with traditional calculation results,the BP artificial neural network better reflects the geological conditions of the research mine areas and produces more objective,accurate and reasonable results,which can be applied to predict the height of water flowing fractured zones.

Height Detection and Analysis of Water Flowing Fractured Zone of Coal Face

Taking 91105 working face as the research object, the observation method of water flowing fractured zone and the layout of mining holes were determined by analyzing the field geological structure. It was shown that the fractured zone height and the ratio given by the measured method were 52.33 and 12.46, respectively. By the numerical simulation method with the software of UDEC, the fractured zone height and the ratio were 42.5 and 10.12. By comparison of measured height data and UDEC numerical simulation, there were some differences between the measured height and the calculated results of UDEC numerical simulation method. The method of simulation can be used as the technical basis for the design of waterproof coal pillar in the future.

Predicting the height of water-flow fractured zone during coal mining under the Xiaolangdi Reservoir

It is very important to determine the extent of the fractured zone through which water can flow before coal mining under the water bodies.This paper deals with methods to obtain information about overburden rock failure and the development of the fractured zone while coal mining in Xin'an Coal Mine.The risk of water inrush in this mine is great because 40%of the mining area is under the Xiaolangdi reservoir.Numerical simulations combined with geophysical methods were used in this paper to obtain the development law of the fractured zone under different mining conditions.The comprehensive geophysical method described in this paper has been demonstrated to accurately predict the height of the water-flow fractured zone.Results from the new model, which created from the results of numerical simulations and field measurements,were successfully used for making decisions in the Xin'an Coal Mine when mining under the Xiaolangdi Reservoir.Industrial scale experiments at the number 11201,14141 and 14191 working faces were safely carried out.These achievements provide a successful background for the evaluation and application of coal mining under large reservoirs.

Optimum Calculation of Coal Pillars in Inclined Weathered Oxidation Zone

In the mining process of coal mine,waterproof coal pillars should be set between the weathered oxidation zone and the first mining face.In order to determine the reasonable upper limit of the first mining face of Hongyi Coal Mine,the waterproof coal pillar needs to be wide enough to resist the lateral hydrostatic pressure of the oxidation zone,and to ensure that the top plate aquifer does not run through the water guide crack zone,while also liberating as much stagnant coal as possible.In this paper,the first coal mine face’s waterproof coal pillar was calculated using conventional and optimized calculation methods,taking into account the dip angle of the coal seam,the height of the water-guide crack zone,and the rock shift influence zone,and finally the upper limit of the first face of Hongyi Coal Mine was determined.

综采工作面采动覆岩导水裂隙带发育高度综合研究

针对因煤层开采易导致上覆岩层产生裂隙,贯通地下含水层引发矿井水灾的问题,以盘城岭煤业150105工作面为研究背景,采用理论公式、现场井下仰孔注水测漏法和钻孔电视成像探测法,以及FLAC3D和UDEC数值模拟综合分析导水裂隙带的高度和发育规律。理论计算导水裂隙带的最大高度为81.56 m;通过井下仰孔注水测漏法监测3个钻孔的注水渗透量梯度临界值为12 L/min,通过临界值判定导水裂隙带高度为78.56~79.99 m;通过钻孔电视成像探测法观测钻孔内裂隙分布判定导水裂隙带高度为78.39~79.46 m;利用FLAC3D和UDEC数值模拟,根据覆岩塑性区变化特征,当工作面推进至180 m时,裂隙发生贯通,塑性区最大高度达到76.4 m,并根据覆岩塑性区变化、垂直应力分布、垂直位移云图分析了导水裂隙带发育规律的3个阶段。对不同方法下的导水裂隙带高度进行了相互验证。

高家堡井田二盘区导水裂隙带高度实测研究

为了查明煤层顶板导水裂隙发育规律,采用地面钻孔分段注水测试和钻孔窥视方法实测了高家堡井田204工作面和205工作面煤层顶板导水裂隙带发育高度。研究结果表明:(1)205工作面DT1钻孔位置煤层顶板导水裂隙带发育高度为327.75 m,裂采比25.81。(2)204工作面DT2钻孔位置煤层顶板导水裂隙带发育高度为197.85 m,裂采比35.33。(3)高家堡井田二盘区导水裂隙带实测结果丰富了黄陇煤田综放采煤覆岩破坏规律。

缓倾斜煤层综采工作面覆岩“两带”高度研究

随着矿井开采向深部发展,矿井水害风险逐渐增加,准确掌握工作面采空区覆岩“两带”即垮落带、导水裂隙带发育高度,对矿井顶板水害防治、合理留设防隔水煤(岩)柱意义较大。本文采用理论计算、UDEC数值模拟、压水测试3种方法,对青云煤矿020202综采工作面覆岩“两带”发育高度进行了研究,3种方法相互验证,最终得出该工作面垮落带最大高度为10.3 m,冒采比为4.12;导水裂隙带最大高度为41.6 m,裂采比为16.64,该结果可以为矿井的安全生产提供科学指导。

地质构造带大巷顶板淋水注浆封堵技术

以中六运输大巷断层影响范围内顶板淋水防治为工程背景,提出采用RSS化学浆液对顶板淋水区进行快速封堵,同时采用U型钢架棚+聚氨酯浆液强化围岩支护强度,避免围岩变形产生新的导水裂隙。结合现场条件,对具体采用的顶板淋水注浆封堵技术方案进行设计,并进行工程应用。现场应用后,中六运输大巷顶板淋水问题得到较好解决,巷道围岩变形控制在安全范围内,采用的技术方案可满足中六运输大巷后续安全使用需要。

老虎台矿28002工作面综放开采导水裂隙发育规律

为研究综放开采覆岩导水裂隙带发育高度,以老虎台矿区28002工作面为研究背景,分析了老虎台矿区内12组工作面导水裂隙带高度实测数据,得到了导水裂隙带高度计算的回归公式,并通过理论计算和数值模拟相结合的方法,对导水裂隙带发育高度进行预测,结合钻孔窥视,观察裂隙带上方含水层的岩性特征。结果表明:经验公式、回归公式和数值模拟结果显示28002工作面采后导水裂隙带发育高度分别为131.49、117.34和153.9 m。其发育最高点均位于计军屯组的油母页岩内,而油母页岩作为良好的隔水层为顶板防水提供了有效保障;通过钻孔窥视,计军屯组上方的页岩含水层裂隙发育程度较好,易形成导水通道,威胁工作面的安全回采。

高庄煤业隐蔽致灾地质因素分析及防治措施

煤矿隐蔽致灾地质因素具有隐蔽性、时变性、突发性等,探测和预防难度大。煤矿开采过程中的几大灾害事故,多数与隐蔽致灾地质因素紧密相关。通过开展煤矿隐蔽致灾地质因素普查,推动煤矿企业强化安全基础工作,提升安全保障能力,进一步减少事故总量,有效防范和遏制煤矿重特大灾害事故,为煤矿制定防灾措施和安全生产奠定基础。

综采一次采全高工作面导水裂隙带发育高度研究

本文以东坡矿东部区为工程背景,对工作面导水裂隙带发育高度进行研究分析。优化经验公式参数,建立导水裂缝带高度预测模型,通过搜集多个矿井数据,对工作面导水裂隙带影响因素进行PAST软件相关性统计分析,确定影响因素及其比值由重到轻分别为:采深(0.93)、关键层间距(0.82)、工作面斜长(0.68)和采高(0.35),并建立导水裂隙带解析式。通过与实测数据对比,确定预测模型绝对误差保持在4.40%以内,符合误差要求。

Forecasting water disaster for a coal mine under the Xiaolangdi reservoir

Xin’an coal mine, Henan Province, faces the risk of water inrush because 40% of the area of the coal mine is under the surface water of the Xiaolangdi reservoir. To forecast water disaster, an effective aquifuge and a limit of water infiltration were determined by rock-phase analysis and long term observations of surface water and groundwater. By field monitoring, as well as physical and numerical simulation experiments, we obtained data reflecting different heights of a water flow fractured zone (WFFZ) under different mining conditions, derived a formula to calculate this height and built a forecasting model with the aid of GIS. On the basis of these activities, the coal mine area was classified into three sub-areas with different potential of water inrush. In the end, our research results have been applied in and verified by industrial mining experiments at three working faces and we were able to present a successful example of coal mining under a large reservoir.

基于微震监测技术的煤矿顶板水害预测

以亭南煤矿307工作面为工程背景,通过模拟分析导水断裂隙带高度来验证微震监测数据实时监测导水断裂带高度的可靠性,并利用数理统计方法分析了微震事件与顶板涌水量的关系。研究结果表明:307工作面在不同推进距离条件下,微震事件集中分布于覆岩破坏严重区,能够反映覆岩破坏情况及导水裂隙带发育高度;工作面回采数值模拟结果与微震监测事件变化规律基本一致,导水裂隙带高度发育特点为“前期增长快,中期增长慢,后期达到平衡”;307工作面微震监测数据事件数与同时间段内的涌水量相关性显著,涌水事件和微震事件的发生具有特定的滞后效应,采用合适的滞后微震数据做预测能更好地提高涌水量预测准确度。

Forecasting of destroyed height of overlying rock with the top coal caving based on ANN

Analyzed the rule of the Water Flowing Fractured (WFF) zone's development during the fully mechanized top coal caving.Six influence factors of WFF's height were selected,viz.mining thickness,base rock thickness,dip angle,uniaxial compressing strength of roof,mudstone proportion in overlying rock,and structure of overlying rock. The height-forecasting model of WFF was established based on the Artificial Neural Net-work techniques,and was applied in the first fully mechanized top coal caving face under sea in China.

矿井涌水量预测及防治水建议

含水层、老窖水以及采空区积水等水源极易发生透水事故,为煤矿安全生产带来巨大隐患。以某煤矿14152综放工作面为例,观测冒落带与导水裂隙带发育高度,利用富水系数比拟法准确预测矿井涌水量,并针对该煤矿实际情况合理提出防治水措施,对安全生产,提高经济效益具有重要意义。

PCA-WNN模型在导水裂隙带高度预测中的应用研究

导水裂隙带是煤层顶板水害的主要通道,准确预计导水裂隙带高度是预测和防治煤层顶板水害的首要任务。基于导水裂隙带发育的复杂性及其影响因素之间的相关性,结合煤矿生产实际和工程地质理论,选取采高、工作面斜长、硬岩岩性比例系数、采深和煤层倾角作为主控因素,利用线性回归拟合及灰色关联分析法分析各主控因素与导水裂隙带发育高度的相关性。将主成分分析(principal component analysis,PCA)与小波神经网络(wavelet neural network,WNN)相结合,通过PCA消除各主控因素间的相关性及冗余信息,构造无相关性的主成分作为WNN的输入因素,建立导水裂隙带高度预测的PCA-WNN模型。结果表明:PCA-WNN模型能有效消除因素间的相关性,预测相对误差为-6.66%~6.13%,平均4.46%,较单纯的WNN模型预测精度高且稳定。将该模型应用于山东新巨龙煤矿1302N工作面,得到了较为准确的预测结果,为导水裂隙带高度预测提供了新方法。

特厚煤层开采覆岩高位离层突水危险性评价

煤矿覆岩离层突水危险性预测评价是制定科学防治水方案的基础和依据。为提高特厚煤层开采覆岩高位离层水害防控的精准性,首先根据离层与开采煤层之间距离及其与导水裂隙带范围的空间关系,判断出特厚煤层开采形成的高位离层位于导水裂隙带顶部附近,并分析了高位离层水涌突的3个基本条件,即相对封闭的可积水离层空间、离层补给水源和下渗的导水裂隙通道;然后在底板突水危险系数法的基础之上,提出了离层突水危险系数的概念,建立了高位离层水涌突危险性评价方法和危险性分级标准;最后采用该评价方法对郭家河煤矿1305工作面顶板离层突水危险性进行了评价,并根据郭家河煤矿和崔木煤矿其他工作面顶板离层突水危险性评价结果对该方法进行了验证。结果表明:郭家河煤矿1305工作面顶板离层突水危险性等级为安全,即不会发生离层突水;郭家河煤矿和崔木煤矿其他工作面顶板离层突水危险性评价结果与实际突水情况基本一致,验证了该评价方法的有效性。该研究成果可为黄陇煤田特厚煤层开采顶板离层水害的精准防控提供理论依据。

彬长矿区煤层开采导水裂隙带高度探测及计算

针对彬长矿区煤层开采顶板导水裂隙带发育规律复杂,导致矿井水害影响评价难度大的问题,通过分析典型工作面的涌水情况,对比不同开采参数下工作面涌水差异特征,初步得出不同工作面长度对导水裂隙带的差异性影响;以现场实践为指导,提出“采前背景条件探查、采中水位动态监测、采后综合测试”的煤层开采全过程导水裂隙带高度综合实测方法;基于矿区内大量导水裂隙带高度实测结果,分析得出彬长矿区导水裂隙带发育规律呈现明显的工作面长度控制效应,采长175~240m时导水裂隙带发育高度较大,采长80~151m时导水裂隙带高度相对较小,在同一工作面长度控制下,导水裂隙带高度随采高呈非线性增长的规律;根据导水裂隙带高度变化规律,采用非线性回归分析方法,分别拟合出2种开采参数下导水裂隙带高度计算经验公式,并分析了公式的适用范围;采用推导的经验公式对区域内新开采工作面影响白垩系洛河组含水层程度进行分析,结果表明所得经验公式可以较好地评价工作面受洛河组含水层充水的影响程度,与《煤矿防治水手册》推荐的经验公式相比其计算精度明显增加。研究成果可对彬长矿区和周边相似条件矿井导水裂隙带高度的确定提供较好的参考,同时丰富了我国西部侏罗纪煤田煤层顶板导水裂隙带的研究成果。

蒙陕接壤区典型煤层开采地下水系统扰动的定量表征

生态脆弱区煤矿高强度开采扰动地下水系统,造成水资源损失。选取黄河流域中段蒙陕接壤区东南—西北走向剖面典型浅部开采和深部开采矿井为研究对象,利用覆岩破坏理论分析、数值模拟、井下实测3种方法,并通过周边地质和开采条件相似矿井实测数据对比,综合确定了浅埋复合煤层开采和深埋单一煤层开采导水裂隙带发育高度,根据导水裂隙带与顶板主要含/隔水层空间位置关系,划分出浅埋煤层开采直罗组−志丹群含水层充水模式和深埋煤层开采直罗组含水层充水模式;通过概化不同含水层充水模式地下水流系统,构建了典型煤层开采地下水三维非稳定流数学模型,并利用Visual Modflow软件建立了2种工况地下水流数值模型,对接续期2023—2024年工作面开采地下水流场和水资源损失量进行了定量预测,并利用涌水量实测数据验证了模型可靠性。结果显示:受扰动的浅埋区志丹群、直罗组含水层,以及深埋区直罗组含水层地下水呈现向采空区汇集现象的同时,流场也伴随采后煤层顶板二次稳定结构的形成而逐步恢复,但围绕采空区附近,充水含水层地下水流场表现出局部高水力梯度现象;另外,2种采煤工况接续期水资源损失量年均分别达到200万m^(3)和730万m^(3)以上。研究结果为区域水资源损失超前精细控制和矿井水资源化利用提供了参考。

复杂地质条件下覆岩导水裂隙带钻孔窥视与实测分析

为探明郭屯煤矿复合煤层开采过程中覆岩导水裂隙带的发育规律,共计施工3个地质钻孔,分别对3上煤层,3上煤与3煤复合煤层开采导水裂隙带进行实测。通过监测钻孔单位时间与单位进尺冲洗液消耗量与水位变化量,并利用钻孔窥视技术对导水裂隙带高度进行预测。将多种实测方法下分析的导水裂隙带高度进行对比,结果表明:钻孔冲洗液漏失主要原因是洛河组上部的衍生的大量水平裂隙,3上煤单煤层开采导水裂隙带发育高度181.93 m,复合煤层开采导水裂隙带发育高度259.03 m。