钻孔灌注桩泥浆流变特性及水力参数研究分析

钻孔灌注桩泥浆主要功能是稳定孔壁、悬浮和携带钻渣,其泥浆流变特性和水力参数对泥浆作用至关重要。本文首先实验研究了钻孔灌注桩泥浆的流变特性;然后推导出了钻孔灌注桩泥浆流变参数的计算公式;最后分析了钻孔灌注桩泥浆稳定孔壁、携带和悬浮钻渣的特性,对评价和优化钻孔灌注桩泥浆具有重要理论和实践意义。     

砂土地基中钻孔灌注桩施工技术

文章以神华煤液化项目大型设备组装厂房工程中钻孔灌注桩为例，论述了在全部为粉细砂地层中进行钻孔灌注桩施工时，针对粉细砂层易坍塌、透水性强导致孔壁稳定性差的特点，通过控制泥浆稠度、钻进速度等施工技术措施，保证了成桩质量，取得较好效果，可为今后类似的桩基施工提供借鉴。     

沿海灰岩地区钻孔灌注桩成孔技术

大连北方生型容器厂位于人工回填海岸,地基工程设计采用钻孔灌注桩,要求桩端全断面进入持力层。在素填土中成孔要用好泥浆,及时吓钢护筒,避免钻孔塌、漏、扩径;在灰岩溶洞层中成孔要选好钻头,用好泥浆,控制钻进参数,避免钻孔偏斜及卡、夹钻事故;在遇有３￣４层溶洞时采用水下岩石松动爆破工艺,采取有效措施,达到全断面嵌岩。成桩后经检测各荐指标均合格。     

灌注桩钻孔泥浆脱水机具的试验研究

采用卧螺离心机对灌注桩钻孔泥浆进行了脱水试验，简单介绍了卧螺离心机的工作原理和脱水过程，根据脱水效果与成本分析表明：卧螺离心机用于钻孔泥浆脱水具有良好的经济效益和社会效益。     

大口径钻孔灌注桩的施工及断桩处理

在大口径钻孔灌注桩的基础施工中，对第四系覆盖层中砂卵石层、基岩、均采用回转钻钻进，在钻进工艺上，采用泥浆护壁正循环成孔，泵吸后循环清孔，另外还介绍了砼水下灌注断桩事故的处理。     

3PNL离心泵在大口径钻孔中的使用效果

大口径钻孔灌注桩一股采用一次性成孔，因其口径大，钻渣多，孔壁也相对不稳定。为了保护孔壁，需要泥浆保持一定的粘度。由于泥浆的粘度较大，钻渣     

全基岩超深井大口径泄水钻孔施工技术

马钢(集团)总公司南山矿业公司凹山露天采场泄水钻孔为全基岩超深大口径钻孔，介绍了其钻头、泥浆、钻进参数的选用及采取的一些技术措施。     

钻孔灌注桩泥浆流变性能评价方法探讨

粘度是评价钻孔灌注桩泥浆性能的重要参数之一。由于钻孔灌注桩桩径大,泥浆循环速度低,剪切速率低,评价石油钻井和地质勘探泥浆流变性能的方法不适合评价钻孔灌注桩泥浆粘度。首先分析了钻孔灌注桩循环速度,推出其剪切速率分布;然后分析了旋转粘度计的剪切速率,提出了低转速的粘度计更适合评价钻孔灌注桩泥浆;最后推导出了塑性粘度、有效粘度和动切力的计算公式,对准确评价钻孔灌注桩泥浆具有重要理论和实践意义。     

钻孔灌注桩施工中的几个问题探讨：以上海华夏门广场工程为例

针对华夏门广场钻孔灌柱桩施工中有关循环用泥浆指标，围护桩施工方法等展开讨论结合工程实践提出了关于泥浆指标变动范围，围护桩施工的跳打方式等观点。     

PAA泥浆在会泽矿区水平钻孔中的应用

会泽矿区水平钻孔地层复杂,钻孔坍塌、缩径严重,试验采用PAA泥浆,取得较好效果。介绍了PAA泥浆的配方、配制方法和应用效果。     

CSAMT 法在辽西康杖子区深部探矿中的应用

可控源音频大地电磁法(CSAMT)具有探测深度大、横向分辨率高、抗干扰能力强的特点,在深部找矿勘探中有着重要的指导意义。肖家营子铜钼矿床是辽西地区一个大型矽卡岩型金属矿床,大部分矿体是隐伏矿体,矿区外围的康杖子区与本区有相似的成矿地质环境,成矿地质条件优越.矿体与围岩电性差异明显,通过应用CSAMT,矿体具有低电阻特点,根据成果推断解释,对深部有利成矿部位进行了钻探验证,取得了理想的探矿效果,在矿区外围取得第二深度空间找矿重大突破。     

Recent advances in aquaculture in Japan

Conclusions During the last ten years, aquaculture, especially mariculture has undergone remarkable expansion to counter-balance the gap between the supply and demand of fishery products in Japan. Its expansion has also been supported by the traditional preference of the Japanese people for seafood. Mariculture is now being forced to change its structure due to adverse economic circumstances such as the rise in the cost of energy, feeds and other materials for culture, low market prices, deterioration of environmental conditions, and many other factors. Before these constraints can be resolved, advanced scientific knowledge and technologies must be integrated to develop new types of aquaculture. Expansion of maricultural activities to more open-sea and off shore areas would be one route to follow. Technologies for the development of formulated diets not only for young but also for adults and larvae, establishment of feeding standards, prevention of epizootic diseases must support the establishment of modern aquaculture.The culture-based fisheries, or marine ranching, is becoming a subject for further development in Japan. Much research work has been conducted with a great degree of governmental support. Establishment of a net work of seedstock production farms has made it possible to carry out releasing experiments on a large scale. A newly integrated restoration system could be developed on the basis of these experiments, even though the profits resulting from the artificial restoration of stocks is not thouroughly verified at present. The commencement of a national scheme for culture-based fisheries would be a manifestation of the enthusiasm of the Japanese fish industry.     

花岗岩地区地下水水文地质特征分析

通过对泰安市岱岳区花岗岩地区地下水的形成条件、地下水类型、分布状况、水文地质特征以及地下水补给、径流、排泄条件的分析,指出了花岗岩地区供水方向。     

Geography in general education in Nigeria

This paper traces the development of geographic education in Nigeria and examines the views of geographers, other academics, students and the public at large about the importance of geography. Geography's value is immense despite the non-professional nature of the discipline. Nevertheless, there is a need to define geography's status and ensure career prospects for students. The Nigerian Geographical Association (from classroom teaachers to top geographers) must promote geography, improve its status in schools and universities, and continuously restructure its content and methods to address pertinent social needs.     

Trends in landslide occurrence in Nepal

Nepal is a mountainous, less developed kingdom that straddles the boundary between the Indian and Himalayan tectonic plates. In Nepal, landslides represent a major constraint on development, causing high levels of economic loss and substantial numbers of fatalities each year. There is a general consensus that the impacts of landslides in countries such as Nepal are increasing with time, but until now there has been little or no quantitative data to support this view, or to explain the causes of the increases. In this paper, a database of landslide fatalities in Nepal has been compiled and analysed for the period 1978–2005. The database suggests that there is a high level of variability in the occurrence of landslides from year to year, but that the overall trend is upward. Analyses of the trends in the data suggest that there is a cyclicity in the occurrence of landslide fatalities that strongly mirrors the cyclicity observed in the SW (summer) monsoon in South Asia. Perhaps surprisingly the relationship is inverse, but this is explained through an inverse relationship between monsoon strength and the amount of precipitation in the Hill District areas of Nepal. It is also clear that in recent years the number of fatalities has increased dramatically over and above the effects of the monsoon cycle. Three explanations are explored for this: land-use change, the effects of the ongoing civil war in Nepal, and road building. It is concluded that a major component of the generally upward trend in landslide impact probably results from the rural road-building programme, and its attendant changes to physical and natural systems.     

2010年的美国铀矿业

2010年,美国铀矿总共施工7 209个钻孔,总进尺1 493 520 m;生产铀1 628.55 t;铀矿业总支出费用为2.773亿美元,其中铀矿地勘费支出为3 450万美元,占铀矿业总费用的12.44%。铀矿地勘钻探费用为4 460万美元,占铀矿业总费用的16.08%。     

地下水环境中的硫代砷研究进展

硫代砷是富硫化物地下水中砷的重要形态,对环境和人类健康有潜在威胁。目前硫代砷研究程度尚低,本次主要针对国内外地下水（地热水）中硫代砷的存在形态,水文—生物—环境地球化学过程,样品保存,定量检测方法等方面进行研究。结论如下:pH, 氧化还原电位,硫化物含量和微生物作用等是影响地下水中硫代砷稳定存在和形态分布的重要因素。含铁矿物能与水中的硫代砷形成配位键对其进行吸附,吸附性普遍弱于（亚）砷酸盐,因此,地下水中硫代砷可能表现出更强的迁移性。用于硫代砷检测的自然水样在采集中可采取过滤,速冻,厌氧和低温短期保存的操作流程,以减缓该形态的转化甚至消失。色谱联用ICP-MS系统可用于自然水样中硫代砷的分离定量检测,紫外—可见分光光度法和X射线吸收光谱法在不同场景下也可对硫代砷进行定量和表征分析。地热水和浅层地下水中均可能存在硫代砷,由于水样中硫代砷的不稳定性,室内检测和分析难以准确反映现场过程,因此,野外样品保存技术和现场检测方法的更新可能在未来有更大研究空间,值得进一步探索。     

MapSUV系统在惠民县土地勘测定界中的应用

该文介绍了土地勘测定界的专业背景知识及MapSUV的相关信息,阐述了MapSUV系统在惠民县土地勘测定界的应用,以及外业获取数据及内业处理的主要工作方法,最后对该系统在土地勘测定界中的应用前景进行了展望。     

环境地球化学研究近十年若干新进展

环境地球化学学科在中国生态文明和美丽中国建设、国际环境公约履约及过去全球变化研究中发挥着越来越大的作用。本文简要回顾了中国过去十年在环境地球化学领域的部分研究进展,介绍了汞、持久性有机污染物和其他重金属污染物长距离传输研究进展;总结了汞、镉、锑、铊等非传统稳定同位素在地表生物地球化学循环过程中的同位素分馏规律及污染来源和环境过程示踪方面的研究进展;回顾了传统稳定同位素地球化学与污染示踪及过去全球变化方面的研究进展。指出了以上研究方向还存在的问题及未来研究方向。