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粘土矿物改性在岩土工程中的应用 总被引：2，自引：0，他引：2
１ 问题的提出粘土矿物广泛存在于各种地质体中。特殊的晶体结构赋予粘土矿物许多特性。例如吸水性、膨胀性、可塑性、离子交换性和吸附性能等等。粘土的高比表面积使其具有较强的活性。目前矿物学家和材料学家的兴趣主要集中在研究粘土矿物的表面物理化学性质,采用各种方法改变和提高其活性,扩展它的应用范围,提高粘土的附加值。但是,在岩土力学工程中,却要抑制和降低粘土矿物的活性,特别是与水的结合能力。在工程界,凡涉及岩土工程的领域,都有一个灾害防治（包括地质灾害和工程灾害）和软基处理问题,其中重点处理和防治的对象就… 相似文献
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三峡库区泥灰质岩石及其残坡积土化学成分及粘土矿物的定量研究 总被引：5，自引：0，他引：5
由于二峡库区三叠系巴东组(T2b)泥灰质岩石特殊的化学矿物组成和所处亚热带湿热环境,决定了三峡库区移民迁建场地工程地质环境的复杂性。通过泥灰质岩石及其不同风化岩和残坡积土的化学成分、粘土矿物成分定量研究和扫描电镜观察,揭示了CaCOs溶蚀和粘土矿物富集过程及粘土矿物的复杂成分,发现了风化过程中伊利石()向伊利石／蒙脱石(I／S)混层粘上矿物的转化,解释了岩土工程性质恶化的原因,从而提高了地质研究和地质灾害研究的水平。 相似文献
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为证实本文第一部分所阐述的关于粘土质点间相互接触对饱水粘土的物理——力学性质影响这一观点,我们将下列试验研究综述如下:1.在粘土矿物悬浮液中,凝聚结构形成的研究;2.单矿物型粘土泥浆强度性质的研究;3.不同温度条件下,粘土泥浆双电层 相似文献
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层柱粘土材料制备与应用研究 总被引：9，自引：1，他引：9
简述了层柱粘土矿物材料研究与应用的现状和进展。利用粘土矿物蒙脱石作母体，通过大体积的铝、锆、硅等交联剂插层可制成层柱多孔材料，在酸催化、氧化还原催化中均有十分广阔的应用前景。研究表明，改进制备工艺后可提高层柱蒙脱石的热稳定性、比表面积和催化活性；通过酸或表面活性剂等预处理，再进行粘土的支撑，可以调节和控制层柱粘土的结构与性能；采用有机改性和模板导向等技术，可获得孔径介于大微孔和中孔之间的新型层柱粘土矿物材料，并应用于大分子催化反应与吸附，为粘土矿物材料合成和应用开辟了新方向。 相似文献
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陕西宝鸡市新近系硬粘土包括风成三趾马红土和“古三门湖河湖相堆积”的硬粘土,是西北地区典型的硬粘土地层之一,也是控制宝鸡市北坡黄土塬边大型滑坡分布的关键地层。为了深入认识该类特殊岩土,尤其是膨胀性粘土矿物（蒙脱石和其混层矿物）,根据该类地层的空间分布特征采集了30多个岩土样品,在宏观与细观结构特征分析基础上,利用移液管法、精细X-射线衍射（XRD）技术、乙二醇与乙醚极性有机分子吸附法,完成了样品粒度成分的定量分析和粘土矿物的精细测定,分析其膨胀势,并结合区域滑坡分布与工程边坡病害,揭示其边坡灾害效应。 相似文献
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粘土矿物颗粒极细,粒径一般小于2μm,其中含有有机质、碳酸盐、游离铁、非晶质等,因此样品必须经过严格分选后才能正确鉴定粘土矿物.阐述了利用比重和粒径的差别用水簸(淘洗)的方法分离出粘土矿物和非粘土矿物,然后利用不同粘土矿物的重力或离心力下降的难易程度(决定于粒度的大小和比重的差异)加以分离.由于提取的粘土矿物单一结晶片很细小,所以介绍了研究粘土矿物最常用的方法——X射线衍射样品的制备方法. 相似文献
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林茂福 《矿物岩石地球化学通报》1985,(3)
随着粘土矿物的理论体系和系统研究方法的建立,以及有机物与粘土矿物间相互作用的资料的积累,本世纪六十年代初诞生了有机粘土化学。这门新兴学科主要研究粘土、粘土矿物与各种有机物之问的反应,有机粘土复合体的形成、性质和转化,以及它们在工农业、科学技术领域中的实际应用。它的出现,打破了有机化学和无机化学间的传统界限,在元素地球化学、矿床学、有机地球化学和粘土矿物的研究上具有重要的意义,在化工、工程、农业,环保和国防建设上也有着广阔的前景。 相似文献
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广西红黏土矿物成分分析 总被引：4，自引：0，他引：4
黏土矿物成分对其工程力学性质具有显著的影响。目前,在黏土矿物种类鉴定方面已有一些成熟的方法技术,而对黏土的矿物成分定量分析尚没有成熟的方法。本文基于X射线衍射试验、全化学元素分析、Bogue法和K值法,对广西武鸣、桂林两地红黏土的矿物成分进行了定性鉴定和定量分析。研究结果表明:(1)桂林、武鸣两地红黏土的主要矿物均为高岭石、三水铝石、针铁矿,桂林红黏土还含有一定量的石英。(2)武鸣红黏土的矿物成分及其含量依次为:高岭石(74.0%)、三水铝石(12.53%)、针铁矿(2mm, 2.22%)、针铁矿(2mm, 8.37%)。(3)桂林红黏土的矿物成分及其含量依次为:高岭石(56.59%)、三水铝石(11.44%)、针铁矿(15.61%)、石英(12.45%)。 相似文献
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滇西北红粘土的工程地质特性及其灾害效应 总被引：1，自引：0，他引：1
在野外地质调查的基础上,结合室内土工试验,系统分析了滇西北红粘土的物质组成、物性特征和工程地质特性,并以此为基础探讨了其地质灾害效应。研究结果表明：滇西北红粘土粒度组成主要以粘粒为主,粘土矿物成分比较复杂,在丽江以南其矿物成分主要以高岭石（K）为主,在丽江以北则以伊利石/蒙脱石（I/S）混层矿物为主。此外,滇西北红粘土具有含水量高、重度低、塑性高、膨胀性弱等物性特征,在天然状态下比较稳定,但是随着含水量的增加其土体强度大大降低,易引发滑坡、水土流失等地质灾害。 相似文献
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《矿物学报》2013,(Z1)
In the past four decades, there is a growing use of surfactant modified clay complexes in wide range of applications. The mostly used surfactants to modify the swelling clay minerals are cationic surfactants, such as quaternary ammonium, which consists of two distinct moieties, a hydrophilic head, where the positive charge is concentrated, and a hydrophobic hydrocarbon chain tail. During the surface modification, this kind of surfactant molecules attach on the inner and outer surface of clay minerals, the hydrophilic surface of raw clay minerals may changed into hydrophobic surface. The changes of organophilicity and hydrophobicity of clay minerals enable them used in more wide fields, such as adsorbents for organic contaminant, geotechnical barriers, filling of nanocomposite, etc. 相似文献
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宁德市位于福建省东北部,其下伏软土具有典型的闽东北第四系软黏土沉积特性,独特的内湾地形又使其兼具与传统浙闽沿海软土不同的物理力学特性。本文结合海岸带地质调查结果,通过环三都澳软黏土的原位测试和室内土工试验,对宁德第四系海相软土沉积特性及物理力学性质进行了系统研究和分析,发现该海相软土具有高压缩性、高液限、高灵敏度的特征,容易受到扰动导致强度的损失,工程建设中及基础设施灾变演化中应加以注意。大量内部孔隙极度发育且亲水性强的硅藻残骸使宁德软土具有很高的比表面积,同时也是令其具备结构性的重要原因,这两点是宁德软土区别于传统软土的显著特征。 相似文献
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Enuvie G. Akpokodje 《Engineering Geology》1987,23(3-4):193-211
A study of the engineering geological properties, distribution and classification of the major superficial soils of the Niger Delta was carried out as part of a study programme to provide the much needed information and data for the infrastructural development of the region. Four major superficial soil groups were recognized on the basis of similarity in geotechnical, geological and geomorphological characteristics. The soils are generally fine grained and their geotechnical properties revealed that they are essentially clays with varying proportions of sand, silt and organic matter. The clay, silt and organic contents increase seawards. The values of the various geotechnical parameters are mainly influenced by the amounts of clay (and/or sand) and organic matter. 相似文献
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The influence of type and amount of clays present in soils on their properties is well understood. The clays exert their influence through large specific surface area and charges on them. Their effect is mostly exhibited through inter particle bonding and subsequent particle associations. The mineralogical influence of soils in water is well documented. However, the change in soil water system because of presence some of the contaminants can greatly influence the soil behaviour. Some of the changes are due to formation of new compounds due to interactions between the soil and pollutant. The paper reports the effect of interaction of kaolinite mineral with alkali on the index properties of soils from which the geotechnical behaviour can be understood. Detailed X-ray diffraction studies have shown that sodium aluminum silicate hydroxide hydrate (NASH) is formed by clay alkali reactions. The type and amount of formation of the compound is influenced by the concentration of alkali solution. While the compound formed is in smaller quantities with 1 N NaOH solution, significantly high quantity is formed with 4 N NaOH solution. Presence of alumina is shown to play a significant role. It was observed that the formation of sodium aluminum silicate hydroxide hydrate is reduced in the presence of alumina. Specific gravity of contaminated clay soil was reduced which confirms the formation of new compounds. Water adsorption and specific surface area of soil are also influenced due to soil alkali interaction. The changes in the free swell and index properties of soil in the presence of alkali have been explained by the changes in soil fabric and the formation of new compound. 相似文献
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Clay deposits in Oltu-Narman basins (Erzurum, northern Turkey) have been studied to determine their engineering properties
and to evaluate their uses for geotechnical applications. These deposits are concentrated in two different stratigraphic horizons
namely the Late Oligocene and the Early Miocene sequences. Clay-rich fine-grained sedimentary units are deposited in shallow
marine and lagoonar mixed environments. Their clay minerals originated by the alteration of Eocene calc-alkaline island-arc
volcanics, preferably from pyroclastics (trachite and andesite flow), which form the basement for the Oltu depression. Smectite
group clay minerals are found abundant in clay deposits. The experimental results show that the clay soils have high plasticity
behaviors and low hydraulic conductivity properties. The optimum water content, the free swell, and the swelling pressure
of clay samples decreased and the maximum dry unit weight of clay samples increased under high temperature. Consequently,
it is concluded that the expanding of clay soils is an important soil problem that cannot be avoided in the significant parts
of Oltu city and its villages. However, the soils of clay-rich layers in the outcrops-section of clay deposits can be successfully
used to build compacted clay liners for landfill systems and to construct vertical and horizontal barriers for protection
of ground water and for preventing soil pollution in geotechnical applications. 相似文献
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The mobility of toxic metals in soils or sediments is of great concern to scientists and environmentalists since it directly affects the bioavailability of metals and their movement to surface and ground waters. In this study, a multi-surface soil speciation model for Cd (II) and Pb (II) was developed to predict the partition of metals on various soil solid components (e.g. soil organic matter (SOM), oxide mineral, and clay mineral). In previous study, the sorption of metal cations on SOM and oxide minerals has been evaluated by thermodynamically based surface complexation model. However, metal binding to soil clay fractions was normally treated in a simplistic manner: only cation exchange reactions were considered and exchange coefficient was assumed unity. In this study, the binding of metals onto clays was described by a two-site surface sorption model (a basal surface site and an edge site). The model was checked by predicting the adsorption behavior of Cd (II) and Pb (II) onto three selected Chinese soils as a function of pH and ionic strengths. Results showed that the proposed model more accurately predicted the metal adsorption on soils under studied condition, especially in low ionic strength condition, suggesting that adsorption of metals to soil clay fractions need to be considered more carefully when modeling the partition of trace elements in soils. The developed soil speciation model will be useful when evaluating the movement and bioavailability of toxic metals in soil environment. 相似文献
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Sudhakar M. Rao 《Engineering Geology》1995,40(3-4):215-221
The presence of allophane minerals imparts special engineering features to the volcanic ash soils. This study examines the reasons for the allophanic soils exhibiting unusual shear strength properties in comparison to sedimentary clays. The theories of residual shear strength developed for natural soils and artificial soil mixtures and the unusual surface charge properties of the allophane particle are invoked to explain the high shear strength values of these residual soils. The lack of any reasonable correlation between ′ (effective stress-strength parameter) and plasticity index values for allophanic soils is explained on the basis of the unusual structure of the allophane particle. The reasons as to why natural soil slopes in allophanic soil areas (example, Dominica, West Indies) are stable at much steeper angles than natural slopes in sedimentary clay deposits (London clay areas) are explained in light of the hypothesis developed in this study. 相似文献
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