泥晶灰岩地层孔壁坍塌掉块现象及处理          下载免费PDF全文

杜金云 《探矿工程》2006,33(8):51-52

在灰岩地区钻探施工过程中，常见孔壁坍塌、掉块现象，尤其在含泥晶灰岩地层分布区钻进过程中，这种现象尤为突出，轻则影响钻探施工效率，重则造成钻探孔内事故。针对孔内坍塌、掉块现象的征兆及特点，提出了相对应的处理办法。  相似文献   

The effect of thermal treatment on the 57Fe Mössbauer spectrum of beryl     

Geraldo Magela da Costa  Gabriel de Oliveira Polli  Márcio A. Kahwage  Eddy de Grave  Antônio Claret Soares Sabioni  Júlio Cesar Mendes 《Physics and Chemistry of Minerals》2006,33(3):161-166

Mössbauer spectra (MS) of blue, green and yellow beryl (ideally Be₃Al₂Si₆O₁₈) containing approximately 1% of iron were obtained at 295 and 500 K. Room temperature (RT) spectra of both blue and green samples showed the presence of an asymmetric Fe²⁺ doublet (ΔE _Q~2.7 mm/s, δ~1.1 mm/s), with a very broad low-velocity peak. There is no clear evidence for the presence of a ferric component. The MS of the yellow sample at RT consists of an intense central absorption with parameters typical for Fe³⁺ (ΔE _Q~0.4 mm/s, δ~0.29 mm/s), plus an apparently symmetrical Fe²⁺ doublet. This sample acquires a light-blue shade upon heating in air at about 620 K. Thermal treatments at high temperatures caused no significant changes in the MS, but the green and yellow beryl acquire a blue colour. All these results are interpreted in relation to the existence of channel water and the distribution of iron among the available crystallographic sites.  相似文献   

Construction Problems on the Karstified Limestone Tuffs of Condeixa, Central Portugal: A Case Study     

M. Quinta Ferreira  J. L. Velho 《Geotechnical and Geological Engineering》2006,24(1):101-116

During the excavations for the foundations of a three storey building on the limestone tuffs of Condeixa, Central Portugal, a large dissolution fissure and smaller dissolution voids were found. Since the area has never been the subject of engineering geology investigation, it was decided to evaluate the risk associated with the construction of the building. These limestone tuffs were formed in a continental environment by the precipitation of calcite carried by the water coming from the large limestone body in the east. The precipitated calcite mixed with the terrigenous materials and around trunks and leaves of plants, originating a very heterogeneous and porous ground, which is characteristic of limestone tuffs. The study started with a detailed geological survey followed by a large number of destructive drillings, located essentially under the pad foundations. The results revealed several karstic cavities with serious problems for the building foundations and the structure, and many smaller dissolution cavities, often filled with clayey soils. The ground treatment solutions used included, dental cleaning, filling with concrete or granular material the dissolution structures accessible at the level of the foundation, reinforcement of the footing and the structure of the building and adding a continuous foundation beam to hold the foundations together. The cost of the engineering geology study, site investigation, ground treatment, and the reinforcement of the foundation and building, increased the total construction cost from 2%, at the design stage, to 4.8%.  相似文献   

桩锚支挡体系在广西寨-任二级公路高边坡治理工程中的应用   总被引：3，自引：0，他引：3  

胡华敏  胡杰刚  俞敏  全洪波  兰高 《中国地质灾害与防治学报》2006,17(3):150-153

(六)寨-(水)任二级公路施工后,滑坡、坍塌、崩塌现象甚多,边坡治理迫在眉睫。桩锚支挡体系是一项主动性加固边坡技术,具结构轻巧、用材合理、施工简单、工期短、费用低等特点。论文通过其在(六)寨-(水)任二级公路K56段高边坡治理工程中的应用,对桩锚支挡体系的设计及施工要点作了介绍。  相似文献   

Effect of heat treatment on tourmaline from Brazil   总被引：4，自引：0，他引：4  

Cristiane Castañeda  Sigrid G. Eeckhout  Geraldo Magela da Costa  Nilson F. Botelho  Eddy De Grave 《Physics and Chemistry of Minerals》2006,33(3):207-216

The crystal-chemical behaviour of tourmaline from Araçuaí, Minas Gerais state, Brazil, when subjected to heating in air atmosphere has been studied by several techniques, including EMPA, UV–Vis, TGA, and Mössbauer spectroscopy. The tourmaline samples are typically intermediate members of the elbaite-schorl series. The origin of colour and of its change after treatment has been discussed in terms of local disorder, presence of metal transition elements, oxidation of ferrous iron at the octahedral site, and simultaneous trap of the excess electron. These findings may be used to enhance the colour in tourmaline crystals or generate wanted colour changes.  相似文献   

旧供水井化学处理方法介绍--以加德满都市旧供水井修复为例   总被引：1，自引：0，他引：1  

章伟民 《水文地质工程地质》2005,32(6):100-101,107

本文以加德满都市旧供水井修复项目为例,针对因滤水管缝隙被化学物质堵塞,导致井出水量逐年减少的旧供水井。通过井下电视摄像系统检查,采用六偏磷酸钠、氨基黄酸等有机酸,结合刷洗、高压喷射等机械方法进行处理,使旧供水井出水量得到明显提高。  相似文献   

生物膜处理技术的研究进展   总被引：3，自引：0，他引：3  

吴会中  单欣  赵琛琛 《中国勘察设计》2005,(11):52-54

本文综述了生物膜技术的发展概况及其传质理论,并且对各种类型生物膜反应器的应用和发展作了简要论述,最后提出了生物膜技术的发展方向。  相似文献   

不正常的自记记录处理及在报表编制过程的处理方法     

程爱珍 《气象研究与应用》2002,23(4):61-62

介绍在处理自记观测记录时,对不正常记录及在编制报表时应采取的处理方法。  相似文献   

耒宜高速公路路堑边坡变形破坏特征及其综合治理   总被引：2，自引：2，他引：2  

肖剑秋  卿笃干  赵海斌  钟辉亚 《工程地质学报》2002,10(1):89-92

耒宜高速公路修建于山岭重丘区 ,沿线地形、地质条件差异较大 ,路堑开挖边坡类型较多 ,特征不一。本文介绍了路堑边坡的主要特征、边坡失稳的主要原因及治理对策。  相似文献   

Hydration and refractive indices of Holocene tephra glass in Hokkaido, Northern Japan     

Yugo Nakamura  Yoshinori Katayama  Kazuomi Hirakawa 《Journal of Volcanology and Geothermal Research》2002,114(3-4)

Refractive indices of incompletely hydrated tephra glasses vary widely. Thus, glass refractive index is not a practical indicator for identifying Holocene tephras. Hydration near the surface of tephra glass shards can be removed by either hydrofluoric acid treatment or annealing for 12 h at 400°C. The annealing procedure is a particularly reliable and simple way to dehydrate tephra glasses. Standard deviations (s) of refractive indices for glasses after 12 h annealing are small (s=0.0014–0.0018), in contrast with untreated glasses (s=0.0034–0.0405). The refractive indices of dehydrated tephra glasses are 0.006–0.014 lower than those of the untreated (hydrated) glasses. Using the 400°C 12-h annealing procedure, values for the refractive indices of eight Holocene tephras in Hokkaido were obtained. These refractive indices are useful indicators for identification and correlation of Holocene tephras.  相似文献