巷道推进方式对断层围岩稳定性影响规律

断层破碎带影响着巷道围岩位移场和应力场分布。基于此，考虑断层破碎带赋存条件下，巷道推进方式对断层围岩稳定性影响，采用FLAC^3D对两种推进方式通过断层时的应力、位移、变形特征及塑性区开展数值模拟分析。研究结果表明：断层破碎带倾角一定时，随着掘进工作面与断层中心距离变近，巷道围岩变形破坏更为剧烈；巷道由上盘向断层推进时的围岩结构体系稳定性高于下盘向断层推进。该研究成果为类似巷道掘进过断层提供了参考。     

程潮铁矿采准巷道围岩稳定性数值模拟研究

松软破碎围岩的巷道支护一直是困扰地下金属矿山生产的重大技术难题。结合程潮铁矿东区的具体工程地质条件和采场布置参数，采用FLAC软件对无断层破碎带无支护、有断层破碎带未支护和有断层破碎带喷锚网支护3种情况进行模拟研究。并从应力、位移和塑性区3方面分析巷道围岩的稳定性。模拟计算表明，现场所采用的支护方案是正确的。     

大采高工作面过断层数值模拟与围岩控制技术

针对王庄煤矿大采高一次采全高过断层技术支护设计问题,采用FLAC3DExtrusion模块对围岩破碎区进行数值模拟,通过fish语言建立巷道开挖模型,对不同工作面推进距离下围岩受断层破碎带影响时的塑性区变化范围与破坏特征进行分析。针对顶板下沉量增大、支架阻力过大以及塑性区破坏范围增大等一系列特征,提出了高初撑力、低采高、低推进速度的挑顶过断层围岩控制技术。经工业性试验检测发现,采用这种技术能够有效控制围岩裂隙发育,降低巷道围岩受断层破碎带的影响程度,提高煤壁的自承能力,实现大采高一次采全高工作面过断层区的安全高效生产。     

断层影响下深部巷道交叉点围岩破坏特征及支护

为了研究断层对巷道交叉点围岩破坏及位移的影响,根据巷道塑性区半径及周边位移公式得出深部巷道围岩变形破坏的影响因素,如高地应力、围岩强度、断层破碎带等,运用FLAC~(3D)模拟巷道交叉点周边应力场分布,发现应力场在巷道穿越断层时受到破碎围岩的影响而产生不连续现象,同时断层构造导致围岩破碎,使底板岩层强度变弱,底鼓问题更加突出.设计了4种不同的支护方案,结合巷道塑性区半径对不同长度的锚杆及有无U型棚架的支护效果进行比较分析.研究分析及模拟结果表明:巷道穿越断层时底板变形量大于顶板变形量;锚杆长度大于塑性区半径时锚固效果较好;锚网索喷+36U型棚支护方案能有效改善巷道变形.     

富水断层破碎带对隧道围岩稳定性的影响

为研究富水断层破碎带对隧道围岩稳定性的影响,以吉莲高速公路永莲隧道工程为背景,对其穿越断层破碎带的一段区域进行变形破坏数值模拟研究,并在此基础上,分析了断层破碎带厚度、倾角以及水头压力对围岩变形的影响。研究结果表明:随着隧道向前推进,掘进工作面岩体位移将在与破碎带间隔距离为9 m时开始呈"瀑布式"增长,而掘进工作面前方岩体松动圈则会在间隔距离6 m时与断层破碎带松动区相连,出现导水裂隙通道,引发突水灾害;隧道掘进工作面靠近破碎带时,其最大纵向位移与破碎带厚度关系不大,而与破碎带倾角和水头压力分别呈指数衰减和线性关系;隧道在破碎带内开挖产生的最大位移分别与破碎带厚度、倾角以及水头压力呈指数衰减、抛物线和线性关系。     

断层对巷道附近塑性区的影响

巷道开挖之后,断层附近的岩体将产生弹塑性区.用FLAC程序分析了断层倾角、断层与巷道的几何关系、断层破碎带厚度等参数对巷道围岩塑性区的影响.结果表明:在巷道开挖的情况下,随着断层与巷道之间距离的增大,断层附近的塑性区范围变化不大;随着断层破碎带厚度增加,断层附近的塑性区范围逐渐增大.     

近断层煤柱巷道围岩变形机理及控制研究

以红岭煤矿近断层煤柱巷道为研究背景,采用理论分析、数值模拟和现场试验等手段,分析了采动影响下断层破碎带围岩应力分布规律,揭示了近断层煤柱巷道围岩应力分布演化规律及变形机理,开发了相应的巷道围岩控制技术。     

深井穿断层破碎带软岩巷道围岩控制技术研究

在总结刘庄煤矿穿断层破碎带软岩巷道围岩破坏特征的基础上,分析了巷道围岩破坏原因,并结合该矿东一轨道大巷施工难点,提出了巷道围岩分步耦合支护技术方案,包括预留巷道围岩变形量、初次锚网索喷耦合支护、滞后围岩注浆加固及帮角和底板锚注加固。现场工程实践表明,采用分步耦合支护技术,巷道拱顶最大下沉量为38mm,两帮最大水平位移量为122mm,底鼓最大位移量为193mm,有效解决了刘庄煤矿深井软岩巷道穿断层破碎带施工围岩稳定控制难题。     

正断层倾角变化对其下盘隧道围岩影响的研究

对在正断层下盘开挖隧道时,断层倾角β对隧道围岩的影响进行了研究.研究发现,β=53°是隧道围岩位移、应力和安全系数等变化的一个转折点;当β为90°～53°时,断层发生了下盘向下移动的活化,断层由正断层转化为逆断层,当β<53°时,断层两盘都有向下的位移,且上盘的位移要大些;断层破碎带对隧道开挖导致的变形有明显的屏蔽作用,这种屏蔽作用主要发生在断层倾角较陡时的情形;隧道围岩最大位移主要分布在隧道的顶部,且围岩最大位移-断层倾角β关系曲线呈近似的"U"字形;围岩强度按安全系数进行折减后就可得到隧道的失稳或破坏状态,隧道围岩稳定安全系数-断层倾角β关系曲线呈近似屋脊形,当β=53°时安全系数最大.结果表明,β的变化对隧道围岩的位移、应力和稳定性有重要影响.     

近断层巷道开挖稳定性分析与支护技术

为研究近断层巷道开挖稳定性及其合理的支护措施,以安里煤矿回风大巷为工程背景,采用FLAC3D对其开挖过程中FD49断层破碎带前后方围岩的应力场、变形场、渗流场以及塑性区进行了系统的分析,并在此基础上研究了锚杆排间距以及注浆加固范围对巷道围岩变形破坏特征的影响。结果表明:近断层巷道围岩越硬,其在靠近富水断层破碎带时的突水变形前兆特征就越不明显,因此,需在预留一定防突厚度的情况下对断层破碎带进行提前疏水降压处理;当巷道开挖揭露断层破碎带后,应对断层破碎带围岩进行注浆加固以及锚喷支护,其中,注浆加固范围宜取3~5 m,锚杆长度和间排距则可选2.4 m和0.8 m。     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

注浆加固技术在十三矿-685 m进风大巷中的应用

针对煤矿开采深度不断向深部延伸,掘进巷道受深部高应力的影响越来越大,巷道围岩整体稳定性差,矿山压力显现越剧烈现象,一般锚网喷加锚索支护无法从根本上控制巷道的变形。总结了平煤股份十三矿-685 m进风大巷注浆加固技术,依据对巷道掘进之后变形监测数据的采集,对巷道变形机理进行分析研究,并对注浆时段进行了合理选择,在对巷道的注浆工艺进行了充分论证的基础上,对巷道进行了注浆。注浆后效果表明:巷道滞后注浆时间段的选择非常重要,巷道在恰当的时间内进行注浆加固施工,能有效控制巷道的变形,巷道注浆后变形量明显减小,岩体的稳定性明显增强,减少了巷道日常维修工作,降低了矿井的生产成本,保障了矿井的安全生产。     

Brief news

正China Minmetals Rare Earth Construction of Jianghua Separation Plant is set to complete at the yearend Civil works of Jianghua Separation Plant have been finished and the company is installing and debugging equipments now.It is estimated that construction of Jianghua Separation Plant will be     

Brief news

正Total transactions of rare earth in Rare Earth Ex-change Center of Hunan South Rare and Precious Metal Exchange neared 40 billion yuan from January to October From the opening in January of this year to the end of October,the total transaction of rare earth products in Rare Earth Exchange Center of Hunan South Rare and Precious Metal Exchange neared40 billion yuan.There are 16 varieties including dysprosium oxide and terbium oxide traded on the exchange center,one of the largest trading platforms for rare earth oxides in China.     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Theoretical basis for optimal collector concentrations and pulp pH values during flotation of sulfide-free minerals

A hypothesis that associates optimal conditions of mineral flotation with a zero charge of their surface is put forward. This hypothesis serves as a basis for a methodology to obtain and verify quantitative physical-chemical models for a minimal necessary concentration of a collector during flotation of sulfide-free minerals. These models may be of use for upgrading engineering processes of flotation and as a job for the concentration plant automation systems. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 89–99, March–April, 2006.