Controlling coal fires using the three-phase foam and water mist techniques in the Anjialing Open Pit Mine,China

Natural Hazards - Coal fires are a serious environment, health, and safety hazard throughout the world. They damage the environment, threaten the health of people living nearby, burn away...     

Poroelastic behaviour of saturated brittle rock with anisotropic damage

A new anisotropic poroelastic damage model is proposed for saturated brittle porous materials. The model is formulated in the framework of the continuum damage mechanics. A second‐rank symmetric tensor is used to characterize material damage due to oriented microcracks. The classic Biot poroelastic theory is then extended to include poroelastic damage coupling. Both the deterioration of elastic properties and poroelastic coefficients is taken into account. A suitable procedure for determination of model parameters from standard laboratory tests is presented. The validity of the model is tested through comparison between numerical predictions and experimental data in various loading conditions. The overall performance of the model is evaluated. The choice of relevant effective stress for the microcrack propagation criterion in saturated cohesive geomaterials is discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

山东灵山岛北背来石剖面下白垩统顺层砂脉的特征及其成因动力学分析*

山东灵山岛北背来石剖面下白垩统莱阳组发育大量砂脉。根据砂脉与层面的关系,将其分为顺层砂脉和非顺层砂脉。前者主要发育在三角洲前缘黑色泥岩中,顶、底界面普遍参差不齐,常与软沉积变形构造共生。在分析砂脉特征的基础上,建立了非地震条件下顺层砂脉侵入的物理模型和公式,推导出液化砂层的深度与侵位深度和上覆沉积层厚度之间的关系,认为形成大型砂脉的液化砂层深度都很大。该实例对研究砂脉的成因、湖泊相关沉积及盆地构造运动具有重要意义。     

青田-仙居地区金银矿化特征及找矿远景分析

浙江青田-仙居地区位于华南褶皱系浙东南褶皱带之温州-临海拗陷内.金银矿化的直接围岩是上侏罗统西山头组晶屑、玻屑熔结凝灰岩.主控矿构造为火山机构及有关的断裂构造.多期次的火山活动、岩浆侵入活动为金银成矿提供热源、热液及成矿物质来源.该区与龙泉遂昌金银成矿带同处于地幔陡变带内,深部构造特征相同或相似.区内构造活动、火山喷发及岩浆侵入频繁而强烈,伴随的多期次热液活动明显.基底岩系为含金变质岩系(陈蔡群、龙泉群),盖层岩系是由基底含金变质岩系重熔或部分同熔形成的中生代火山喷发-沉积岩系.在基底岩系演化过程中,金银等成矿物质发生了活化、迁移、富集或再分配作用,部分在构造有利部位富集成矿,部分则以自然态、游离吸附态赋存在凝灰质岩石中,经多期次热液作用再次被活化、迁移,最终在成矿有利部位沉淀富集成矿.因此,青田-仙居地区具备较好的金银成矿条件,是金银矿找矿的良好远景区.     

引黄隧洞地应力测量

本文应用水压致裂地应力测量法和声发射法,在山西太原引黄工程的两个钻孔中进行了地应力测量,得到了可靠的数据,为隧洞设计提供了依据。文章首先对水压致裂测量方法进行了介绍,然后给出了测量结果。并对隧洞断面的设计和岩爆问题进行了讨论。根据岩爆发生的准则指出,若隧洞走向与最大水平主应力平行,且选择适当断面,将减小岩爆发生的可能性。      

引黄工程AE法与水压法地应力测量对比

本文在说明AE(声发射)法在引黄工程地应力测量实施过程中的作用之后,简要介绍了AE估测法和估测结果,并与水压致裂法测量结果相对比,给出测量结果的评价性结论是两法测量结果近乎一致。AE法估计500m深度最大主应力值为26.7MPa。      

克里雅河上游流域黄土中孢粉组合与环境

对克里雅河上游流域末次冰期以来形成的两个黄土剖面13块样品进行了孢粉分析。分析结果表明, 末次冰期以来该区黄土堆积的植被类型主要是以耐旱的麻黄(Ephedra)、藜(Chenopodiaceae)、蒿(Artemisia)等草本植物为主, 属荒漠草原类型。但期间也出现过具有一定含量的云杉(Picea)、冷杉(Abies)、松属(Pinus)等针叶树花粉, 显示出疏林草原环境。由此表明, 从那时以来的黄土堆积过程中, 在总的持续干旱的荒漠草原环境下也存在相对的干湿波动。     

平庄煤田煤中稀土元素地球化学特征

结合煤田地质特征,对不同矿区、不同煤组的煤进行了稀土元素的含量测试,得出了煤的稀土元素含量变化规律及分布模式,讨论了稀土元素的主要赋存状态、来源、含量异常以及与成煤作用的关系。      

热带大气环流平均状况的研究

应用NMCl7年热带u、v风及OLR资料研究了热带地区大气环流的平均结构和特征。指出热带大尺度环流基本上是由东西向的walker环流和南北向的Hadley环流所组成的。这些环流是由热力作用直接驱动的,它具有高低层风向相反的特征。扰动风场与平均风场有密切关系。西风基本气流对应着扰动动能的极大值而东风则对应着扰动动能的极小值。热带地区存在着明显的辐散辐合作用,它也是由热力作用引起的并与热带对流活动有密切联系。      

SA01 – A Proposed Zircon Reference Material for Microbeam U‐Pb Age and Hf‐O Isotopic Determination

A new natural zircon reference material SA01 is introduced for U‐Pb geochronology as well as O and Hf isotope geochemistry by microbeam techniques. The zircon megacryst is homogeneous with respect to U‐Pb, O and Hf isotopes based on a large number of measurements by laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) and secondary ion mass spectrometry (SIMS). Chemical abrasion isotope dilution thermal ionisation mass spectrometry (CA‐ID‐TIMS) U‐Pb isotopic analyses produced a mean ²⁰⁶Pb/²³⁸U age of 535.08 ± 0.32 Ma (2s, n = 10). Results of SIMS and LA‐ICP‐MS analyses on individual shards are consistent with the TIMS ages within uncertainty. The δ¹⁸O value determined by laser fluorination is 6.16 ± 0.26‰ (2s, n = 14), and the mean ¹⁷⁶Hf/¹⁷⁷Hf ratio determined by solution MC‐ICP‐MS is 0.282293 ± 0.000007 (2s, n = 30), which are in good agreement with the statistical mean of microbeam analyses. The megacryst is characterised by significant localised variations in Th/U ratio (0.328–4.269) and Li isotopic ratio (?5.5 to +7.9‰); the latter makes it unsuitable as a lithium isotope reference material.