Status quo and prospect of the development for underground coal mine refuge chamber

As one form of the energy resources, coal is becoming more and more important. Due to the particularity in coal mine production, mine accidents some time occur in countries all over the world, which result in large casualties and economic losses. As equipment that can provides the miners with an emergency shelter when the coal mine accidents occur, the under ground coal mine refuge chamber is paid more and more attention by coal mine enterprises, and the application of the refuge chamber is increasingly widespread. The general functions, the classification, and the successful applications of the underground coal mine refuge chamber are illustrated first, and the research significance on the tmderground coal mine refuge chamber is stated. Following, the development status quo at home and abroad for the refuge chamber is introduced. Then, the implementation methods for the key functions of the underground coal mine refuge chamber are demonstrated. Finally, the prospect for the development of the underground coal mine refuge chamber is stated.

Destabilization analysis of overlapping underground chambers induced by blasting vibration with catastrophe theory

According to the main characters of overlapping underground chambers, the roof (floor) of two adjacent underground chambers is simplified to the mechanical model that is the beam with build-in ends. And vibration load due to blasting is simplified to harmonic wave. The catastrophic model of double cusp for underground chambers destabilization induced by blasting vibration has been established under the circumstances of considering deadweight of the beam, and the condition of destabilization has been worked out. The critical safety thickness of the roof (floor) of underground chambers has been confirmed according to the destabilization condition. The influence of amplitude and frequency of blasting vibration load on the critical safety thickness has been analyzed, and the quantitative relation between velocity, frequency of blasting vibration and critical safety thickness has been determined. Research results show that the destabilization of underground chambers is not only dependent on the amplitude and frequency of blasting vibration load, but also related to deadweight load and intrinsic attribute. It is accordant to testing results and some related latest research results of blasting seismic effect. With increasing amplitude, the critical safety thickness of underground chambers decreases gradually. And the possibility of underground chambers destabilization increases. When the frequency of blasting vibration is equal to or very close to the frequency of beam, resonance effect will take place in the system. Then the critical safety thickness will turn to zero, underground chambers will be damaged severely, and its loading capacity will lose on the whole.

Relationship between the Classification of Rock Surrounding Underground Chambers and the Initial Damage Variations in Rock Masses

On the basis of the relationship between each classification index for underground chambers and the elastic wave velocity of rock mass, a corresponding relationship between the classification of rock surrounding underground chambers and the initial damage variable is established by using the wave velocity definition of the initial damage variable of rock masses. Calculation and analysis of relevant data from a hydropower dam located in Southwest China show that the initial damage variable obtained by means of surrounding rock classification has a close relationship with that calculated by wave velocity, which verifies the rationality of the relationship of the two classification indices. This study establishes a foundation for further damage mechanics and stability analysis on the basis of surrounding rock classification.

Analysis and Design Innovation on Underground Gasifier for Medium-Deep Coal Seam

Over the past 80 years,dozens of underground coal gasification(UCG)mine field tests have been carried out around the world.However,in the early days,only a small number of shallow UCG projects in the former Soviet Union achieved commercialised production.In this century,a few pilot projects in Australia also achieved short-term small-scale commercialised production using modern UCG technology.However,the commercialisation of UCG,especially medium-deep UCG projects with good development prospects but difficult underground engineering conditions,has not progressed smoothly around the world.Considering investment economy,a single gasifier must realise a high daily output and accumulated output,as well as hold a long gasification tunnel to control a large number of coal resources.However,a long gasification tunnel can easily be affected by blockages and failure,for which the remedial solutions are difficult and expensive,which greatly restricts the investment economy.The design of the underground gasifier determines the success or failure of UCG projects,and it also requires the related petroleum engineering technology.Combining the advantages of the linear horizontal well(L-CRIP)and parallel horizontal well(P-CRIP),this paper proposes a new design scheme for an“inclined ladder”underground gasifier.That is to say,the combination of the main shaft of paired P-CRIP and multiple branch horizontal well gasification tunnels is adopted to realise the control of a large number of coal resources in a single gasifier.The completion of the main shaft by well cementation is beneficial for maintaining the integrity of the main shaft and the stability of the main structure.The branch horizontal well is used as the gasification tunnel,but the length and number of retracting injection points are limited,effectively reducing the probability of blockage or failure.The branch horizontal well spacing can be adjusted flexibly to avoid minor faults and large cracks,which is conducive to increasing the resource utilisation rate.In addition,for multi-layer thin coal seams or ultra-thick coal seams,a multi-layer gasifier sharing vertical well sections can be deployed,thereby saving investment on the vertical well sections.Through preliminary analysis,this gasifier design scheme can be realised in engineering,making it suitable for largescale deployment where it can increase the resource utilisation rate and ensure stable and controllable operations.The new gasifier has outstanding advantages in investment economy,and good prospects for application in the commercial UCG projects of medium-deep coal seams.

井下避难硐室系统失效评价与在线监测系统研究

为了实现井下避难硐室的安全管理与灾变应急联动,防止系统功能失效,采用事故树定量分析硐室失效成因与各子系统内在联系,结合工程实践,推导出硐室系统失效经验公式,建立失效评价预警模型。根据井上与井下空间分布特点,提出“双网+双系统”协作架构模式及监测系统的物联网架构;搭建一站式指挥调度专线、双向视频语音等设施,保障了系统在线监测与应急网络安全,扩大了系统协同范围;根据预警模型设计了系统软件的六大功能,完善了系统监测与应急应用,实现了井上、井下信息交互安全畅通。该监测系统已在西南某矿成功应用,有利于降低避难硐室失效事件发生,减少安全检查工作量,提高运维管理效率,提升矿山安全管理智能化水平。

NνDEx-100 conceptual design report

Observing nuclear neutrinoless double beta (0vββ) decay would be a revolutionary result in particle physics.Observing such a decay would prove that the neutrinos are their own antiparticles,help to study the absolute mass of neutrinos,explore the origin of their mass,and may explain the matter-antimatter asymmetry in our universe by lepton number violation.We propose developing a time projection chamber (TPC) using high-pressure ^(82)SeF_(6) gas and Topmetal silicon sensors for readout in the China Jinping Underground Laboratory (CJPL) to search for neutrinoless double beta decay of82Se,called the NvDEx experiment.Besides being located at CJPL with the world’s thickest rock shielding,NvDEx combines the advantages of the high Qββ(2.996 MeV) of82Se and the TPC’s ability to distinguish signal and background events using their different topological characteristics.This makes NvDEx unique,with great potential for low-background and high-sensitivity 0 vββsearches.NvDEx-100,a NvDEx experiment phase with 100 kg of SeF_(6)gas,is being built,with plans to complete installation at CJPL by 2025.This report introduces 0 vββ physics,the NvDEx concept and its advantages,and the schematic design of NvDEx-100,its subsystems,and background and sensitivity estimation.

基于改进突变级数法的引水隧洞施工安全综合评价

为保障引水隧洞施工安全,构建了改进的突变级数法的引水隧洞施工安全评价模型。首先分析引水隧洞施工安全突变特征,构建了引水隧洞施工安全评价指标体系;然后利用ISM-ANP组合赋权方法,获取定性和定量的评价指标,提升评价数据的可靠性;进一步基于ISM-ANP组合赋权结果和突变级数理论构建改进的突变级数综合评价模型。最后以某引水隧洞工程作为评价对象,运用模型对引水隧洞施工安全状态进行评价分析。结果表明:某引水隧洞工程施工安全评价等级为一般,引水隧洞施工过程中存在一定安全隐患;提出的改进突变级数安全评价方法精度较高,可为引水隧洞安全评价提供理论参考。

高地应力下深部硐室底鼓破坏围岩稳定性分析

为研究西部山区高地应力作用下深部硐室的稳定性问题,根据普氏压力拱理论,综合考虑深部硐室冒顶,片帮以及底鼓破坏,建立了高地应力下深部硐室底鼓破坏模式,基于极限分析上限法和非线性Hoek-Brown破坏准则,推导了该破坏模式下深部硐室的围岩压力理论公式,求解了该破坏模式下深部硐室围岩压力上限解,并将本文结果与数值模拟和已有成果进行对比分析。此外,通过该破坏模式研究了各参数对围岩压力和潜在破坏面的影响。结果表明:(1)随着初始地应力场参数中σ_(V)和λ增大,深部地下硐室围岩压力q逐渐增大,硐室围岩潜在破坏面逐渐增大,其中σ_(V)表现尤为显著;(2) Hoek-Brown破坏准则参数中GSI、σ_(ci)和m_(i)的增大对深部硐室围岩稳定性有明显的提高效应,而D增加则会降低硐室围岩的稳定性;(3)随着底部压力相关系数μ增加,深部地下硐室顶板和两帮的围岩压力表现为减小的趋势。研究成果可为深部硐室的支护设计提拱有效的理论支撑。

不同工法对高边墙超大断面地下硐室结构变形及应力响应分析

为了分析不同条件下高边墙超大断面地下硐室结构变形及应力响应,文中建立了施工过程中高边墙超大断面地下硐室结构模型,分析了不同围岩等级下6种工法下高边墙超大断面地下硐室结构的应力及变形。结果表明,随着施工步数的不断增加,所有工法下拱顶的沉降量及隆起量均表现为先快速增加后稳定的变化规律,这为高边墙超大断面地下硐室结构的施工方案优化奠定了基础。

金属矿山TBM地下始发硐室群设计及关键施工技术研究

针对金属矿山TBM地下始发硐室群建设重点技术,分析TBM地下始发硐室群设计依据,提出一体化组装始发与分体组装始发硐室群组成布置及各硐室结构参数计算方法。以某金属矿山TBM工程为例,综合考虑TBM设备、组装吊装设备、地质条件因素及安全因素等,分别得出两种方案中始发硐室群各硐室结构参数,最后通过分析工程量、工期等,比选得出最优方案,并根据最优方案介绍TBM始发硐室群施工关键技术。研究结论可为类似工程提供借鉴依据。

大型地下水封石油洞库主洞室群间距分析

大型地下水封石油洞库往往由多个洞室构成,在工程设计中洞室群之间的距离不仅影响洞室围岩的稳定性,同时还能够影响工程建设的经济性。目前大型地下水封石油洞库地下洞室群间距多是根据洞室截面尺寸和洞室围岩质量,按照工程经验来确定,缺乏合理的解释。通过数值分析,模拟实际工程地下洞室开挖过程,根据围岩的空间位移分析洞室群中洞室开挖对其相邻已开挖洞室围岩的影响,确定其影响距离,从而提出合理的洞室间距。数值分析以某地下水封洞库为例,分析8种不同洞室间距工况下两相邻洞室围岩变形变化规律及其相互影响,构建了大型地下水封石油洞库地下洞室围岩关键位置位移立方与洞室间距之间的关系,为该地下水封石油洞库设计提供了参考。

在倾倒边坡中建设地下调压室的工程地质研究

扎拉水电站调压室建在山体倾倒边坡内,对该边坡及围岩稳定性的系统研究至关重要。根据岩体结构和变形破坏类型的差异,采用岩体结构、岩层转角、风化等定性因素结合波速比定量因素进行综合分区;通过现场超常规原位试验,结合反演计算,综合提出各区适宜的岩体抗剪强度参数;采用数值分析法模拟倾倒边坡变形破坏模式,并通过多种解析法校验边坡稳定性。结果表明:边坡倾倒岩体可分为层状弯曲区、碎裂拉张区、散体坠覆区;厂后倾倒边坡的主要失稳形式为拉裂-滑移-剪断和块体卸荷崩落;在倾倒边坡稳定性评价中,安全系数应取现行技术标准规定范围内的较大值,有利于保障倾倒边坡滑移稳定和坡内洞室围岩变形稳定。研究成果解决了地质条件局限和水工结构要求之间的突出矛盾,在中国水利水电建设中具有开创意义,可为倾倒边坡中工程建设提供参考。

超大断面破碎软岩硐室围岩稳定性及控制技术研究

针对超大断面硐室围岩失稳问题,以锦丰金矿地下搅拌站超大断面硐室为研究对象,利用矿山地质钻孔数据库建立矿区岩石质量指标模型,并基于该模型选择搅拌站建设最优位置为150 m中段。通过实验室试验、现场调查及地应力测量确定围岩参数及应力分布特征,利用Phase2岩石力学软件对硐室开挖后的稳定性进行数值模拟分析,根据分析结果并结合工程类比法,提出管缝锚杆+挂网+湿喷混凝土+树脂锚杆+长锚索+壁后注浆+防底鼓反拱混凝土联合支护方案对围岩进行支护。采用数值模拟及现场应用效果监测方法对加固效果进行评价,结果表明:加固后的硐室最大变形量为31 mm,最大主应力为25 MPa,锚杆(索)均未发生破坏,混凝土衬砌所有单元的安全系数均大于1.2,支护结构处于合理有效的受力状态。采用该联合支护方式加固后的硐室处于稳定状态,支护效果良好,相关研究成果对类似工程具有重要借鉴意义。

大型水电站地下厂房岩壁梁施工技术

为解决大型水电站地下厂房岩壁梁施工质量问题,文章以福建省云霄抽水蓄能电站为研究对象,结合场区工程地质条件,针对主厂房和尾闸室2处岩壁梁的岩壁开挖、支护锚杆安装和混凝土浇筑施工展开研究,研究结果表明,文中提出的分区开挖、光面爆破、两臂凿岩台车配合人工安装锚杆、跳仓浇筑混凝土的施工方法,有效保证了主厂房和尾闸室的岩壁梁施工质量,减少了后期补强加固工作,节约了工程投资。

松软破碎硐室群围岩应力分布及综合加固技术

采用现场试验与测试、理论分析、数值模拟相结合的研究方法,开展了山西潞安屯留矿井底车场松软破碎硐室群围岩应力分布与综合加固技术研究。硐室群围岩属于中等地应力场下的松散破碎节理化软岩;围岩应力分布特征表现为:在硐室交叉处和拐角处,出现应力集中与二次叠加,应力峰值达到原岩应力的2～3倍;高压注浆后进行高预应力、强力锚杆与锚索支护是松散破碎围岩有效的综合加固方式。高压注浆可充填和黏结裂纹,提高节理化岩体的完整性与强度,并可提高锚杆与锚索锚固力,有利于支护阻力的传递与扩散。高预应力、强力锚杆与锚索能在围岩内形成拱形的压应力加固区域。井下试验表明:综合加固技术有效控制了松软破碎硐室群围岩变形,保持了其长期稳定。

瞬变电磁法探测地下洞体的有效性

瞬变电磁法对于施工区地表有较强的适应能力，工作效率较高。选用适当的装置可将瞬变电磁法应用于地下洞体的探测，其数据处理解释是采用全期定义将实测瞬变衰减曲线转换为视电阻率—深度曲线，根据地下洞体的瞬变电磁响应特征分析等视电阻率曲线的形态来确定洞体的存在。此方法已通过多次实际应用取得了良好的地质效果。在１９９３、１９９７年两次北京门头沟区老窑勘查工程中由瞬变电磁法圈定出的老窑经钻孔验证成功率达８０％，证明了该方法探测地下洞体的有效性。

高地应力环境下硐室开挖围岩应力释放规律

为研究高地应力环境下硐室掘进引起的围岩应力时空变化规律,以某地下工程模拟试验硐为例,开展了原地应力测量,应用压磁电感法高精度应力测试系统对地下硐室挖掘过程中围岩应力变化的全过程进行了跟踪监测。结果表明:高应力区试验硐掘进引起的围岩应力变化有应力释放、应力调整和应力平稳3个阶段;垂直于硐壁方向的应力变化最显著,距离硐壁0.6 m处原地应力基本完全释放;平行于硐壁方向的应力变化较小,释放掉原值的20%,应力在放炮时瞬间释放完毕;观测到最小主应力在调整阶段有2 MPa左右的应力加强现象。

岩体参数影响大型地下洞室群围岩稳定的灵敏度分析

结合某水电站超大型地下洞室群施工过程中围岩稳定问题 ,通过岩体弹塑性理论分析以及数值模拟对岩石物理力学参数 (弹性模量E ,泊松比 μ ,粘结力C以及摩擦角 φ)不同组合的多种方案计算和分析 ,得到各岩体物理力学参数对洞室围岩稳定影响程度大小 ,为工程勘测设计和现场施工提供了较有价值的参考。

地下洞室围岩稳定性分析方法简述

随着可持续发展战略的提出,地下工程的开发和利用显得尤为重要。地下洞室围岩稳定性是整个工程中的关键问题,现今对地下洞室围岩稳定性研究的分析方法有很多,为了明确各种研究方法的优缺点以及适用范围,本文对现有地下洞室围岩稳定性分析方法进行了分类总结,用系统性的方法从定性、定量、可靠度等方面考虑,主要包括洞室的整体稳定性分析和洞室局部块体的稳定性分析,研究结果对地下洞室围岩稳定性设计及计算有重要的意义,最后对相关研究的现状和发展趋势做了简述。

洞室层裂屈曲岩爆的突变模型

建立了洞室层裂屈曲岩爆的突变模型,得出了洞室层裂屈曲岩爆在准静态破坏条件下的演化规律。引入一个函数表征内层岩体对外层岩体的约束作用,使洞室层裂屈曲岩爆模型更接近实际,更能反映层裂屈曲岩爆的演化规律。此外,还建立了动力扰动下洞室层裂屈曲岩爆的非线性动力学模型。研究结果表明: 洞室层裂屈曲岩爆的演化过程复杂;洞室层裂屈曲岩爆与否,不仅取决于岩体的内因如几何尺寸和岩石的性质等,还取决于外部作用力的大小和方式;动力扰动与粘弹性层状结构岩体的响应存在着非线性关系;该模型对扰动频率非常敏感,扰动频率满足一定条件是动力扰动下洞室发生层裂屈曲岩爆的必要条件;而模型对扰动力幅反应不敏感;在动力扰动下,洞室层裂屈曲岩爆演化过程中,竖向压力起决定性作用。