A case study of water inrush incident through fault zone in China and the corresponding treatment measures

In 2010, a water inrush accident through a fault with a high flow rate occurred at Tianzhuang coal mine in Jining, Shandong Province, China, which was subject to the fault excavation. Grouting is an important treatment method before and after water inrush accidents. In this paper, the evolution of this water inrush accident is studied, and the effective treatment method is presented. The obtained results indicate that groundwater from Ordovician limestone aquifer 28.5 m below the floor flowed into the roadway through the fault zone. Results also show that this water inrush through the fault zone can be divided into a flow rate steady increase phase, a rapidly increase phase, a decrease phase, and a steady phase. The first two phases resulted from permeability increase of the fault, which was caused by seepage failure, and water level of the aquifer led to last two phases. Additionally, grouting using the ground borehole successfully controlled this water inrush accident, and it is proven to be a valid method.     

东滩煤矿奥灰放水试验数值模拟

奥灰水是东滩矿下组煤安全开采的主要水害威胁和重点防治对象。东滩矿下组煤底板奥灰水压高达7.20~11.46 MPa,在不考虑底板受采动破坏影响下,奥灰对17煤的突水系数为0.077~0.158 MPa/m,最小值亦接近现有规程标准上限值(0.10 MPa/m)。为了查清奥灰含水层水文地质条件进而制定合理的奥灰水防治措施,基于矿井的水文地质条件及奥灰放水试验,建立了适合本矿井的水文地质模型,并利用地下水模拟软件Visual Modflow,计算了奥灰含水层水文地质参数。通过验证,该水文地质模型能够客观的反映奥灰天然流场,为今后预测矿井涌水量、奥灰疏降水量提供了依据。      

基于脆弱性指数法的韩城矿区11号煤层底板突水危险性评价

在全面分析韩城矿区地质与水文地质条件的基础上,应用相关因素分析方法,提出研究区煤层底板奥灰含水层突水的指标体系,并以多个典型煤矿为例,重点分析了受奥灰含水层威胁最严重的11号煤层底板突水的影响因素;构建了有效隔水层厚度、褶皱规模、含水层富水性、断层规模4个评价指标;采用脆弱性指数评价方法对11号煤层底板突水的危险性进行了分区。      

徐州矿区奥灰岩溶水突出的原因与防治

徐州矿区开采深度大,水文地质条件复杂,水害严重。主要突出水源为奥陶系含水层。突水原因主要有:底板隐伏陷落柱或断层导水;底(顶)板含水层与奥灰含水层对接;顶板冒落裂隙带导通断层对盘的奥灰含水层;奥灰水通过基岩隐伏露头侧向补给矿井。其防治对策为:引进先进技术手段,探查分析奥灰岩溶水发育规律;分区隔离开采,完善防排水系统;注浆封堵突水通道;排供结合,综合利用。      

丰予井田地下水化学特征分析及意义

了解地下水化学特征及其形成作用对于快速识别矿井突水水源、防止矿井突水具有重要意义。在系统分析丰予井田水文地质条件的基础上,运用各常规离子与TDS（溶解性固体总量）的二次拟合曲线、Piper三线图、离子浓度变异系数、地下水Stiff图、TDS等值线图、Gibbs图以及离子比例系数图对各含水层的地下水水化学特征及形成作用进行分析。研究结果表明:各含水层的离子浓度变异系数均小于1,离子的分布比较稳定;山西组和太原组的水化学类型均为HCO₃·Cl-Na+K·Ca,且Na++K+与TDS浓度均较大,山西组和太原组是相对封闭的含水层,新生界和奥陶系的水化学类型为HCO₃-Ca·Mg;水岩作用是影响各含水层化学成分的主要作用,碳酸盐岩溶解、硅铝酸盐溶解以及蒸发岩溶解是影响地下水化学成分的主要因素。      

Using numerical simulation for the prediction of mine dewatering from a karst water system underlying the coal seam in the Yuxian Basin,Northern China

Water inrush from a karst aquifer threatens mine safety in North China because of the special hydrogeological conditions. This paper systematically analyzes the regional hydrogeological conditions of the Cambrian–Ordovician limestone karst aquifer in the Yuxian Basin. Conceptual and mathematical models of karst water flow system are established, and the karst water flow system is simulated by the finite-difference method. The numerical model is checked using hydraulic head from karst water observation holes, and the sensitivity of hydrogeological parameters is analyzed. Further, the risk of water inrush from the karst aquifer underlying the coal seam in the second mining area of the Beiyangzhuang Mine in the basin is evaluated by the water inrush coefficient method. Based on the critical hydraulic head for mining safety, the rate of mine dewatering is simulated for the three stages of the mining plan with the numerical model. The results show that the risk of water inrush in the second mining area is high. The rate of dewatering in the three stages without grouting is 1300, 1860, and 2050 m³/h, respectively, and with local grouting is 1020, 1550, and 1700 m³/h, respectively. Dewatering combined with grouting not only ensures coal mine safety, but also significantly reduces the rate of dewatering. The prediction method of mine dewatering has practical significance in engineering applications.     

红岭煤矿水文地质特征及充水因素分析

通过对矿区含、隔水层及断层带水文地质特征的分析和井下水文地质现象的观测,认为目前矿井开采煤层较浅,以二1煤顶板直接含水层充水为主,水量不大;但随采掘的延深,煤层下伏的太原组灰岩和奥灰含水层,会在断层的影响下,与其它含水层发生水力联系,对矿井开采形成威胁。根据对矿井充水因素的分析结果,指出目前矿井的充水强度不大,充水通道主要为断层带,在开拓-800m水平时,应注意构造破坏或隔水层薄弱地段,此地段有可能出现奥灰水突入矿井的危险。为防止矿井突水,提出了建立健全地下水观测系统,加强井下钻探和物探工作,重视邻近矿井老窿水监测等矿井水害防治工作建议。     

顶板离层水突涌模式及预防技术模拟研究

为预防顶板离层水突涌产生的安全事故,提出了部分充填方案进行模拟研究.首先通过现有资料总结分析全国发生的多种离层水害事故,深入研究离层积水致灾模式;然后以陕西某矿首采区1307工作面的离层水害事故为例,分析其水文地质条件、上部含水层和离层水突涌的关系,利用3DEC数值软件模拟工作面顶板离层空间发育特征;最后根据该矿的实际...     

范各庄矿12煤底板突水过程模拟分析

以范各庄煤矿水文地质条件为基础,建立了承压水上采煤的岩体水力学模型,应用岩石破裂过程渗流-应力耦合分析系统(RFPA2D-Flow)模拟分析了范各庄矿12煤层底板开采扰动下,裂隙形成、扩展到突水通道最终贯通形成突水的全过程。通过对损伤区分布、应力场和渗流场的演化分析,揭示了开采扰动及水压驱动下完整泥岩底板由隔水岩层到突水通道的演化过程,对突水通道进行了模拟定位,并对不同水压条件下含水砂岩层对底板突水的影响进行了分析。结果表明:12煤底板突水问题取决于含水砂岩中的水压力,在假设隔水层厚度不变时,水压力与突水系数呈正相关关系,随着水压的增大突水越易发生。该研究为12煤底板突水预测与防治提供了理论依据。      

煤层底板破坏的断层效应模拟及其在防治水中的应用

梁北煤矿已发生5 次寒武系灰岩底板突水事故,造成重大经济损失。根据矿井的水文地质条件,建立了煤层开采的FLAC 数值模型,利用岩石力学及渗流力学理论,分别模拟了无断层和有断层条件下煤层底板采动破坏带的演化规律,重点讨论了断裂深度及断层空间位置对底板破坏深度的影响。结果表明,断层的存在可使底板采动破坏深度增加20%~33%,断层是突水重点防范区域,遇断层前10 m 直到过断层15 m 须加强防治水工作。根据模拟结果设计了梁北矿11041, 11151,11111 三个工作面底板的注浆加固工程,重点注浆层位分别为底板破坏范围和寒武系顶部裂隙发育带,注浆工程增强了底板的阻水能力,实现了工作面的安全回采。     

徐州三河尖煤矿充水因素分析及防治水对策

在介绍矿区地质及水文地质条件的基础上,对矿井的充水因素进行了较为全面的分析,指出矿井的主要充水水源是山西组砂岩裂隙水、太原组灰岩岩溶裂隙水和奥陶系灰岩岩溶水;充水通道主要是断层破碎带和隐伏陷落构造,其次是采矿形成的冒落带和导水裂隙带。结合历年的突水资料,分析了三河尖煤矿历次发生水害事故的原因。针对煤矿充水特征,提出了在预防煤层顶板砂岩裂隙水和太原组灰岩岩溶水时,要以超前疏放为主,对奥陶系灰岩岩溶水,则应以＂防＂为主。     

义煤集团西部四矿奥灰水防治技术研究

2006年曹窑东井27080工作面突然发生大型奥灰滞后突水,最大涌水量达到1693m^3／h,通过矿井水文地质条件分析,曹窑东井及相邻西部四矿大部分区域已处于“突水危险区”。为避免奥灰突水灾害再次发生,提出了“以防为主”的预防奥灰突水的技术手段和方法步骤,以探索深部煤炭开采的防治水工作。     

东胜煤田乌拉素矿区水文地质特征及充水因素研究

近年不断发生的突水事故,给煤矿安全生产带来严重威胁,研究矿区水文地质特征,分析矿井充水因素有重要现实意义。根据东胜煤田乌拉素矿区地质勘探和水文地质资料,对煤层开采导水裂隙带高度进行计算,结果表明:直罗组底部、含煤系地层的裂隙承压水含水层和上部煤层采空区内的积水,是煤层开采时矿井涌水的主要充水水源,矿井充水通道有断层裂隙带、封闭不良钻孔、采动导水裂隙带;其中导水裂隙带会将上部煤层采空区积水导通,使充水强度增大,矿坑涌水量增加。建议开采过程中要做到边探边采,探采结合,预防突水问题。     

Application of an Improved Flow-Stress-Damage Model to the Criticality Assessment of Water Inrush in a Mine: a Case Study

This paper presents a case study of water inrush on a mine working face from roof strata. The flow-rock failure process analysis (F-RFPA^2D) code with an improved flow-stress-damage (FSD) model was adopted to perform the failure and coupling analysis. The improved FSD model was used to represent the permeability variation at the four stages (elastic, damaged, cracked, and crack closure) of the rock failure process. The fracture initiation, propagation, and coalescence in the stressed strata and the seepage field evolution in the stress field are represented visually during the whole process of water inrush. The failure zone with high permeability induced by mining disturbance becomes the water-conducting zone after full excavation of the coal seam. The height of the water-conducting zone obtained in this study is in reasonable accordance with that predicted by an empirical formula. It is definitely clarified that the water inrush from the roof strata is induced by the failure zone full of vertical coalesced mine fractures. It is unlikely that roof accidents resulting in water inrush would occur if the water-conducting zone does not grow upwards into the aquifer. The main task for mine extraction under a confined aquifer is to locate the aquifer and find the maximum height of the water-conducting zone, which is very important for mine construction and support design.     

矿山水文地质结构及其采动响应

本文以谷德振先生创立的岩体工程地质力学理论为指导,在水文地质结构概念的基础上提出了矿山水文地质结构的概念,结合我国煤矿的宏观地质背景及矿山水害的研究基础,基于矿山水文地质结构对矿山水害类型进行了重新划分。从突水水源、导水通道以及采掘活动3个致灾危险源出发,结合矿山突水溃砂灾害、底板突水实例,对矿山水文地质结构的采动响应进行研究,为矿山水害防治和矿山安全地质工作提供了一种新的思路和途径,显示了岩体工程地质力学在煤矿水文地质工程地质研究中的重要指导作用和强大的生命力。     

贵州赫章县珠市铁矿山矿井突水机制研究

贵州地区岩溶普遍发育,岩溶区矿产资源丰富。由于含矿层及上下部地层含水性强至极强,矿产开采过程中水害问题突出。大型地下堰塞水体是形成矿井突水的主要水体之一,因其隐蔽性高,防范难度极大。阐明大型地下堰塞水体成因及其形成矿井突水的特点,对矿山生产防水治水有重要意义。以赫章县珠市铁矿山2015年“11·22”突水事故为例,在对突水矿井开展技术调查的基础上,结合矿山水文地质条件,通过对断层构造部位的岩溶发育特点、地下水径流、赋存状态以及形成矿井突水的水源类型、各类水体形成突水特征等分析,揭示了岩溶区大型地下堰塞水体的形成机制; 阐明了该类水体形成矿井突水的一般特征及突水征兆; 明确了造成赫章县珠市铁矿山矿井突水的水源为大型地下堰塞水体,事故系矿井爆破掘进过程中揭穿大型地下堰塞水体下部岩溶管道所致。大型地下堰塞水体形成矿井突水有其独特性,针对性地开展矿井防治水工作,及时采取合理、有效的防治水措施意义重大。     

Impact of karst water on coal mining in North China

Coalfields in North China encompass more than ten Provinces. They contain six to seven coal seams in the Permo-Carboniferous strata. The lower three seams account for 37% of the total reserves and are threatened with intrusion of karst water from the underlying Ordovician limestone. Hundreds of water inrush incidences have occurred, in which a large amount of water suddenly flows into tunnels or working faces under high potentiometric pressure. Over 50 mines have been flooded over the last 30 years. Large-scale dewatering or depressurizing of the karst aquifer was considered essential to avoid water inrushes and keep the mines safely operational. This practice, however, has caused sinkholes, dry springs, water supply shortage, and groundwater contamination in the surrounding areas. One alternative water control measure is to make full use of the rock layer between the coal seam and the karst aquifer as a protective barrier to prevent or constrain water flow from the underlying aquifer into the mines. Grouting is effective when the hydrogeological conditions are favorable to this technique. Proper design of the grouting program and experience of the contractor are also important for a successful application.     

良庄煤矿51101W工作面突水机理

新汶矿业集团良庄煤矿51101W工作面因底板突水导致工作面被淹。通过水质分析,判定突水水源是奥陶系灰岩岩溶水。根据工作面附近的地质构造推断,突水通道为延伸到奥陶系与石炭系不整合面的铲状滑动断层(该断层最大落差只有7 m左右)。结合工程实践指出,在该矿,根据断层落差来判断断层导水性的观点并不正确,并提出了“用断层落差(H)与其倾角(α)之比值(S)来说明断层对突水影响程度”的观点。      

矿井涌水量动态预测非稳定释水-断面流法

我国北方煤田上覆地下水系统含水层以砂岩为主,是矿井主要充水水源。除浅部、露头区外,上覆砂岩地下水系统总体上构成非径流型蓄水构造,弹性贮存是其地下水主要赋存状态,压力传导、局部渗流为地下水动力学模式,矿井涌水主要为承压含水层弹性释放。非充填开采,煤层上覆地层周期性冒裂形成冒裂二元结构体,其自身释水(弹性、重力)与其外侧含水层断面弹性释水叠加形成矿井涌水。冒裂二元结构体释水随冒裂周期发生,时间短暂。外侧含水层断面释水可用非稳定流定降深沟(渠)流方程描述,进而获得外侧含水层断面释水单宽流量。外侧含水层释水断面随冒裂周期性延展累积,迭代更新,矿井涌水流量随之变化。在研究、刻画外侧含水层释水断面延展、迭代时空规律基础上,给出含水层断面释水流量预测方法、公式,与冒裂二元结构体自身周期性释水流量叠加,获新的矿井涌水量预测方法—非稳定释水-断面流法。     

某铁路隧道隧址区水文地质条件分析与洞身涌水量预算

通过详细分析隧道址区水文地质资料,认为石炭系灰岩、三叠系中统河湾组白云质灰岩和上统大水塘组下段安山玄武岩为强含水层组,大量的岩溶发育于石炭系灰岩和三叠系中统河湾组白云质灰岩中。以井水断层及太元背斜为界,将研究区分为太元背斜和街子坡复式向斜2个水文地质单元,并对各单元中水量、水质与地下水的补给、径流及排泄条件等进行了说明。采取并测试了13组地下水同位素样品,结果发现,区内地下水均来源于大气降水。应用地下水动力学和降水系数法对隧道洞身的涌水量进行了预测,推断隧道的正常涌水量为56 880m3/d,最大涌水量为68 300m3/d。为防止隧道塌方,提出了"短进尺、快循环、弱爆破、少扰动、紧封闭、超前注浆"的施工方法,并要求在施工中做好超前地质预测工作。