湖南天井冲石煤矿区温冲石煤钒矿矿床地质特征

在系统研究湖南宁乡天井冲石煤矿区温冲石煤钒矿矿区地质、矿体地质特征、矿石地质特征的基础上,运用统计学方法对该区真厚度、发热量和钒含量进行统计分析和相关分析,并总结控矿条件,确定找矿标志。     

深圳地区花岗岩球状风化体地下分布规律统计分析

深圳花岗岩发育地区球状风化体(俗称孤石)广泛分布,对地下工程建设产生了不利的影响.通过对深圳地区花岗岩孤石大样本的统计分析,得到如下统计结论:深圳地区花岗岩孤石主要成份是微风化花岗岩,60％以上分布在强风化花岗岩层中,残积层和全风化层中也有分布,孤石层面分布高程集中在40.00～70.00m(黄海高程)区间内;80％的孤石揭示“厚度”不超过2.50m,三分之二花岗岩孤石主要发育一层,随着发育层数的增多,出现频率锐减.     

Effects of land use,slope gradient,and soil and water conservation structures on runoff and soil loss in semi-arid Northern Ethiopia

April lightning production in Richmond County, Georgia, from 1995 to 2003 is considered with regard to the associated risk to golfers and spectators at the Master's Golf Tournament and courses throughout the county. An examination of the April lightning climatology of Georgia, focusing on Richmond County, reveals a minimum in lightning activity during the time of the tournament (the first full week of April). A discriminant analysis of Richmond County lightning production utilizes several meteorological variables in order to discern between three categories of April lightning days: little or no lightning activity, minimal lightning activity, and high lightning activity. The analysis distinguishes relatively well between the categories with only 13.5% of the events misclassified. A composite regional analysis of the three lightning categories illustrates the environmental differences between these events. Although the little or no lightning and high lightning categories are somewhat similar environmentally, the intensity of features separates these events and allows for interpretation. The statistical and synoptic analyses together emphasize the importance of low-level instability and frontal proximity and intensity in enhancing lightning production in thunderstorms during April in and surrounding Richmond County. A multitude of meteorological conditions can lead to thunderstorm development. Localized studies of these environments, especially during times of major outdoor sporting events, are needed to help mitigate the risk associated with lightning.     

Seismic fragility assessment of low-rise stone masonry buildings

Many historic buildings in old urban centers in Eastern Canada are made of stone masonry reputed to be highly vulnerable to seismic loads.Seismic risk assessment of stone masonry buildings is therefore the first step in the risk mitigation process to provide adequate planning for retrofit and preservation of historical urban centers.This paper focuses on development of analytical displacement-based fragility curves reflecting the characteristics of existing stone masonry buildings in Eastern Canada.The old historic center of Quebec City has been selected as a typical study area.The standard fragility analysis combines the inelastic spectral displacement,a structure-dependent earthquake intensity measure,and the building damage state correlated to the induced building displacement.The proposed procedure consists of a three-step development process:(1) mechanics-based capacity model,(2) displacement-based damage model and(3) seismic demand model.The damage estimation for a uniform hazard scenario of 2% in 50 years probability of exceedance indicates that slight to moderate damage is the most probable damage experienced by these stone masonry buildings.Comparison is also made with fragility curves implicit in the seismic risk assessment tools Hazus and ELER.Hazus shows the highest probability of the occurrence of no to slight damage,whereas the highest probability of extensive and complete damage is predicted with ELER.This comparison shows the importance of the development of fragility curves specific to the generic construction characteristics in the study area and emphasizes the need for critical use of regional risk assessment tools and generated results.     

天山石林的景观特征及成因浅析

天山石林,位于新疆天山西段的腹心地区,石林景观千姿百态,多呈石墙状、石芽状、峰丛状、孤峰状、尖顶状、平顶状、蘑菇状、方柱形、浑圆形等。成景岩层为第四纪西域组。成因与节理裂隙、冰雪的融冻、差异风化、重力崩塌、化学溶蚀等地质作用有关。     

抛石爆破挤淤过程的有限元数值模拟

抛石爆破挤淤的过程主要分为4步。第1步是直接进行抛石挤淤;第2步是在堤头前方的淤泥内进行首次堤头爆破,使淤泥的强度降低,抛石和淤泥之间的平衡被打破,抛石向淤泥内滑移和下沉,直至达到新的平衡;第3步是补填后再次进行爆破,并依次循环;第4步是每50m进行一次侧爆。通过改变淤泥强度的方式来代替爆破作用,利用有限元数值模拟方法对这4个过程进行了模拟,在此基础上进行了挤淤效果的预测。通过工程实例,进行了理论预测与钻探、探地雷达实际检测结果的对比,证实数值模拟的结果是正确的。模拟结果表明经过抛石爆破挤淤4个步骤的处理,抛石最终会形成稳定的马蹄形海堤。     

荣成大疃刘家铍矿矿物赋存状态

大疃刘家铍矿铍元素主要以羟硅铍石单矿物赋存在矿石中。以羟硅铍石单矿物存在的BeO占79.45%;少部分分散在其他矿物中,以赤铁矿、褐铁矿中BeO含量较高,其次是绢云母、重晶石等。BeO呈分散状态占20.55%,主要集中在绢云母中,这是由于矿石中绢云母含量高所致,分散状态的BeO无法回收。根据矿石中有用矿物和脉石矿物组合,矿石类型为羟硅铍石-绢云母-碳酸盐岩-长石-石英型铍矿石。     

Atmospheric Dry Deposition to Marble and Red Stone

This paper presents dry deposition flux and deposition velocity of atmospheric particles on white marble and red stone at Dayalbagh, a suburban site of semi arid region, which is 10 km away from the industrial sector of the Agra city where due to agricultural practices vegetation predominates. The wind speed at Agra is mostly in the range of 1–2 m s^–1. The atmospheric calm conditions at Agra in summer, monsoon, and winter seasons are 47%, 35%, and 76%, respectively. Industrial areas of the city are away from Dayalbagh and are located in the NE, E, SE, and SW sectors. The main industrial activities, which are in operation in Agra city and its outskirts, are foundry and forging industry. The other industrial activities in Agra are rubber processing, lime oxidation and pulverization, chemicals, engineering and brick refractory kilns. Dry deposition samples were collected on dry days on white marble and red stone (0.224 m × 0.224 m × 0.02 m) using surface washing method. Both slabs were fixed to an iron stand (1.5 m height) at an angle of about 80 from the horizontal and exposed for 24 h on the roof of the faculty building. The order of deposition flux on white marble is NH₄⁺ > Mg²⁺ > Ca²⁺ > Na⁺ > Cl^– > K⁺ > NO₃^– > SO₄^2– > F^– and that on red stone is NH₄⁺ > Mg²⁺ > Ca²⁺ > SO₄^2– > Na⁺ > NO₃^– > K⁺ > F^– > Cl^–. Average dry deposition flux of major ions varies from 3.4 to 128.5 M m^–2 d^–1. The sum of major cations on white marble and red stone are 516.4 and 450.4 eq m^–2 d^–1, respectively while sum of major anions are 425.3 and 400.4 eq m^–2 d^–1 on white marble and red stone, respectively. Higher deposition of all ions was observed when wind blows from NE as most of the Agra Iron foundries and Ferozabad glass industries lie in this direction. The mean values of dry deposition velocity of ions vary between 0.22 cm s^–1 to 1.49 cm s^–1. Deposition velocity for all ions is higher on white marble than red stone inspite of rougher surface of red stone as compared to white marble. This could be due to the chemical nature of white marble, which is made of dolomite and hence adds significant amount of ions by dissolution during washing. Seasonally the deposition velocity was highest in winter.     

广西某地含月光石辉长辉绿岩石材的初步研究

含月光石辉长辉绿岩体是广西某杂岩体中的一个小岩体,呈岩株状,分布面积约0.22km~2,出露于当地侵蚀基准面上的体积约200万m~3。其岩性为辉长辉绿岩,主要由含铁普通辉石、拉长石及少量橄榄石、黑云母、正长石等组成。据研究,正长石中约有5—10％的发蓝色蛋白光的月光石;岩石的物理技术性能较好,其抛光面呈墨绿色,光泽度达117°,可满足饰面石材的要求。经石材加工厂试生产,其切割性略优于花岗岩,因此认为,该岩体是广西与国内罕见的珍贵黑色花岗石石材资源。     

碎石桩加固高填方地基的试验效果分析

碎石桩作为处理软弱地基土的一种有效手段，往往需要对其试验效果进行分析。评价碎石桩处理后复合地基的性状是否达到地基处理考核指标，并提出可能调整的方案。论文以四川九寨一黄龙机场高填方地基处理工程为背景，介绍了碎石桩法加固软弱土层的现场试验，并对碎石桩处理后复合地基的加固效果进行了检测分析。包括碎石桩体检测和桩间土检测，最后综合室内土工试验、动力触探测试及载荷试验检测结果得出，碎石桩对本工程软弱地基的处理能达到预期的加固效果。其复合地基承载力高于设计要求，具良好的导水性，能有效排出地基中地下水。目前，该试验成果已用于指导机场地基处理与高填方填筑体施工。同时，它对于其它类似工程亦有借鉴意义。