陷落柱突水过程的力学模型

通过分析华北地区强含水岩溶陷落柱突水事例和实验室的模拟试验，证实陷落柱围岩破碎，应力大大降低，是产生自然力压裂的必要条件，而自然水力压裂效应是强含水岩溶陷落柱突水的重要原因。     

弱径流条件下陷落柱柱体活化导水的机理及判据

陷落柱突水事故在我国煤矿时有发生,但其导水机理至今仍不十分明确。为分析在弱径流条件下陷落柱柱体活化导水的机理,可用弹性理论求出在自身重力、周边地应力和地下水压力作用下的陷落柱柱体内的应力分布。根据这些应力分析,分别采用Griffith理论、极限平衡理论和库仑准则,可以推导出柱体的关键层和非关键层的活化导水的判据,并据此判据分析了影响陷落柱柱体破坏导水的有关因素。      

武安煤田隐伏陷落柱发育特征研究

武安煤田岩溶陷落柱相对比较发育,是开采下组煤过程中底板水害的重要导水通道,分析确定陷落柱的发育规律及导水性对矿井安全具有重大作用。在以往采掘和勘探孔揭露的基础上,利用水平分支孔对陷落柱在奥灰中赋存状态和导水性进行探查。依据水平分支孔的岩屑(心)和自然伽马、消耗量等数据发现本区岩溶陷落柱在奥灰中发育形状多为不规则型,中心轴为歪斜型,距向斜轴部距离越近,形状不规则性越明显,陷落柱的长短轴可能发生扭转。该区陷落柱柱体分布符合“三带”理论,多为半整体陷落柱,其导水性与岩溶发育程度和富导水性相关,外围影响带和边缘过渡带普遍导水。     

西山煤田古交矿区陷落柱特征及其导水性分析

在分析区域地质特征的基础上,对西山煤田古交矿区陷落柱的数量、形态特征及分布规律进行了总结。从陷落柱的发育特征出发,对其导水条件进行了研究,认为本区岩溶陷落柱是否突水,关键取决于其是否有导水的力学薄弱通道。研究表明,本区岩溶陷落柱柱体胶结致密,后期活化程度弱,距煤层较近的峰峰组含水层的富水性弱,而煤层与上马家沟组强含水层之间隔水层厚度大,因而,在正常块段开采中,岩溶陷落柱作为集中导水通道导致重大突水的可能性较小。     

淮南寒武纪岩溶陷落柱发育特征及导水性分析

1996年任楼煤矿发生的陷落柱特大突水事故，使“淮南不存在岩溶陷落柱”的认识得到了质疑。通过初步调研，在孔集矿南部的孙家大山一带发现出露于地表的岩溶陷落柱，而谢桥矿煤经三维地震勘探也探测出了发育于寒武纪灰岩中的两个岩溶陷落柱。因其岩溶陷落柱的发育层位、充填物质与华北煤田奥陶纪岩溶陷落柱构成明显的对比。导致了其水文、工程地质特征的特殊性。     

开滦钱家营矿1495E疑似陷落柱探查及综合治理

岩溶陷落柱在我国华北石炭二叠纪煤系地层中广为分布,由于陷落柱贯穿于岩溶发育的奥灰和煤系地层之间,即使陷落柱在天然条件下不导水,但由于后期开采活动对其导水性能的改造,陷落柱往往成为奥灰与煤系地层之间联系的通道,井巷或采煤工作面一旦接近或揭露陷落柱时,可能产生突水,破坏采区划分秩序,严重影响煤矿安全生产。2009年,钱家营矿业公司在1495E风道掘进过程中首次揭露地质异常体,高度怀疑为岩溶陷落柱。该公司采取地面微动地震探测、井下直流电法和井下瞬变电磁等多种物探手段与现场钻探相结合,对地质异常体实际赋存状况进行探查。结果表明,该异常体不含水。但考虑到对物探成果必要的检验以及后续井巷工程和相邻工作面回采对异常体围岩应力平衡的破坏导致可能突水,矿方对异常体实施了钻探探查、建立密闭墙以及异常体注浆治理。治理方案的实施为矿山生产建设顺利展开奠定了基础,保证了工作面、采区科学合理划分,且为同行提供了借鉴经验。     

浅析刘桥一矿岩溶陷落柱发育特征及成因

陈集向斜为刘桥一矿的主体构造,刘桥一矿从1971年建井至今,在井下掘进生产过程中共揭露岩溶陷落柱7个,通过对岩溶陷落柱发育特征资料的收集整理,发现陷落柱分布具有一定的规律性.从构造力学、水文地质方面对岩溶陷落柱的成因进行了分析.     

华北煤田岩溶陷落柱及其突水研究综述及展望

华北煤田岩溶陷落柱（简称“陷落柱”）是地质历史演化过程中形成的产物。80多年来,在中国华北煤田39个矿区煤矿开采过程中共揭露10 000多个陷落柱,因其导致的重大突水淹井事故20余起,研究岩溶陷落柱对系统认识中国矿山岩溶水文地质条件以及防治岩溶水害具有十分重要的理论与现实意义。文章系统梳理、总结了华北煤田陷落柱的发育特征、成因机理、突水机理、探查与防治方法,归纳出近年来华北南缘陷落柱的研究成果,并结合目前华北煤田生产过程中陷落柱研究与水害防治中存在的问题,从陷落柱形成机理与演化过程、小型隐伏陷落柱精细化探查与解译、陷落柱“动态监测—预测模型—突水机理”模式以及陷落柱水害防治技术体系等方面展望了其今后研究趋势及水害防治的方向。      

岩溶陷落柱的形成条件——以范各庄矿为例

岩溶陷落柱是华北石炭二叠煤系中发育的一种特殊地质构造,以其隐蔽性和突发性对煤矿安全生产造成严重威胁。长期以来,开滦范各庄矿深受陷落柱水害威胁,其中1984年范各庄煤矿陷落柱出水淹井造成重大经济损失和人员伤亡。通过范各庄矿井地质资料、水文地质类型划分报告,以及对已发现的陷落柱资料进行分析,在前人理论基础上对范各庄矿陷落柱形成条件总结,认为该区在总体走向为北东向的开平复式向斜构造背景控制下,在奥灰岩溶发育,地下水不断交替,岩体自重应力和真空负压动力及地质构造条件下形成陷落柱。     

煤层工作面内陷落柱综合物探探查

煤层工作面内陷落柱与煤层之间具有显著的电阻率、波速和密度差异,适宜于采用无线电波透视法和震波透视CT法来探测煤层工作面内陷落柱的边界范围;陷落柱体通常裂隙发育,与围岩相比较,其富水陷落柱为相对低电阻率值范围,而不富水陷落柱则为相对高电阻率值范围,因此,可利用煤层底板三维电法来探查底板陷落柱富水性。谢桥矿13218工作面1^#陷落柱的探测表明,该陷落柱范围具有较高的电磁波吸收系数特征和相对较高的纵波波速特征;工作面底板陷落柱向下范围为相对高电阻率值特征,为不富水陷落柱。该综合物探探测结果与实际验证资料基本吻合,有效地指导了本煤层工作面开采及底板煤层工作面的开采设计与施工。     

The terrestrial fauna of the Late Triassic Pant-y-ffynnon Quarry fissures,South Wales,UK and a new species of Clevosaurus (Lepidosauria: Rhynchocephalia)

Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.     

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H₂O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H₂O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.     

Quaternary stresses revealed by calcite twinning inversion: insights from observations in the Savonnières underground quarry (eastern France)

Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ₁ roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).     

HYDROGEOLOGY

正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level     

METAMORPHIC PETROLOGY

正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),     

SERIALS

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GEOPHYSICAL EXPLORATION

正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-     

QUATERNARY GEOLOGY & GEOMORPHOLOGY

正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-     

PETROLEUM GEOLOGY

正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)     

GEOCHEMISTRY

正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861