共查询到19条相似文献，搜索用时 156 毫秒
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适合国情的垃圾填埋场衬垫系统 总被引：10，自引：0，他引：10
发达国家填埋场衬垫标准不适合我国国情。本文根据作者的研究成果及国内外有关研究资料 ,初步研究出了六种适合国情的垃圾填埋场衬垫系统 ,并对有关问题进行了讨论 相似文献
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垃圾填埋场复合衬垫剪切特性单剪试验研究 总被引：1，自引：0，他引：1
针对垃圾填埋工程中复合衬垫的界面抗剪特性,利用改进的叠环式单剪仪,对由砂土-无纺型土工布-土工网格-土工膜-夯实粘土组成复合衬垫进行了整体剪切试验研究。重点讨论了复合衬垫整体单剪试验的应力-位移曲线、相同剪切应力下各个界面的位移大小与变化特征和强度特性。研究结果表明：复合衬垫整体单剪试验的应力-位移曲线在低法向应力试验中没有呈现明显的软化特征,在高法向应力试验中有硬化现象;随法向应力增加剪切破坏面会发生转移;目前常用的把复合衬垫拆分为单个界面进行研究来确定最危险界面的方法不能够正确地反映填埋场中的复合衬垫在加载过程中的衬垫单元的实际受压变形情况和在剪切变形过程中最危险破坏面转移的情况;复合衬垫界面的抗剪强度包线呈现双曲线性质。 相似文献
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填埋场粘性土防渗层中强化微生物对垃圾污染物的净化作用 总被引：3，自引：0，他引：3
如何铺设价廉物关的防渗层,又不需对垃圾渗滤液进行处理,达到环保效果好、成本低的目的,是填埋场防渗衬垫铺设所追求的,但由于科学理论及技术条件的限制,这个目的一直没有达到。通过添加营养菌液强化厌氧微生物对污染物的净化作用,在实验室用土柱进行模拟实验及天然的土柱淋滤净化对比实验,研究了粘性土垫层土中添加营养菌液后,厌氧微生物对垃圾污染物的净化能力的变化,得出了加入厌氧微生物菌液后,可显著地提高微生物在土中对垃圾污染物的净化能力的结论。这为开发价廉物美的垃圾场防渗衬垫打开了思路,为有污染问题的垃圾场提供了一种用微生物治理的方法。 相似文献
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如何铺设价廉物美的防渗层，又不需对垃圾渗滤液进行处理，达到环保效果好、成本低的目的，是填埋场防渗衬垫铺设所追求的，但由于科学理论及技术条件的限制，这个目的一直没有达到。通过添加营养菌液强化厌氧微生物对污染物的净化作用，在实验室用土柱进行模拟实验及天然的土柱淋滤净化对比实验，研究了粘性土垫层土中添加营养菌液后，厌氧微生物对垃圾污染物的净化能力的变化，得出了加入厌氧微生物菌液后，可显著地提高微生物在土中对垃圾污染物的净化能力的结论。这为开发价廉物美的垃圾场防渗衬垫打开了思路，为有污染问题的垃圾场提供了一种用微生物治理的方法。 相似文献
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压实粘土衬垫是填埋场等环境岩土工程中常用的屏障材料,其表面的干燥裂隙可能对衬垫的有效性有一定的影响。将整个衬垫分为受裂隙影响的表面土层和不受裂隙影响的下部土层两部分,把饱和渗透系数和裂隙扩展深度看作随机变量,采用蒙特卡洛法分析衬垫底部污染物相对浓度和通量的概率特征。研究表明,由于衬垫底部出现高浓度（接近于1）的概率较大,这个浓度区间可能比相对浓度的均值高很多,对周围环境污染有较大的威胁,因此确定性方法得到的结果存在较大的风险;考虑表面裂隙导致渗透系数的增大,得到的结果更为合理;保证衬垫足够的厚度可以降低表面裂隙土层饱和渗透系数的变化对衬垫防渗效果的影响;将两层土的渗透系数看作独立随机变量,得到的结果偏于安全。 相似文献
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土工合成材料粘土衬垫(GCL)与土工膜(GM)形成的复合衬垫在垃圾填埋场中的应用日益广泛。我国规范中允许在特殊情况下用GCL代替压实粘土(CCL)做垃圾填埋场的衬垫,但是对于“特殊情况”没有明确说明。本文采用数值方法对复合衬垫中无机污染物的对流和扩散进行了计算,从衬垫底部污染物通量和累积量两个角度对GCL复合衬垫和CCL复合衬垫阻滞污染物运移的效果进行了比较,分析两种复合衬垫的等效性,并研究了GCL复合衬垫的适用范围。结果表明,当渗滤液水头较高时,GCL复合衬垫体现出其优势。 相似文献
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E. M. Frempong 《Environmental Geology》1999,37(3):255-260
An engineering geological investigation has been undertaken of a proposed landfill site in coastal southwestern Ghana which
is characterized by torrential rains, high relative humidity, shallow groundwater conditions and almost surrounded by a ridge.
The study shows that the site has some desirable characteristics such as availability of suitable soils for the construction
of the capping and bottom liners of the landfill, a large tract of land for landfilling operation and its location close to
a major highway. However, the groundwater table was shallow and there was a high potential for leachate intrusion into and
consequent contamination of nearby groundwater abstraction wells and surface potable water sources thereby constituting serious
threat to life. Construction costs could be prohibitive as extensive dewatering and backfilling of vast portions of the project
site would be required to enable the provision of a separation between the shallow water table and the bottom of the landfill.
Received: 20 January 1998 · Accepted: 26 May 1998 相似文献
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针对西北地区特殊的气候条件和砾质土料源丰富的实际情况,提出采用宽级配砾质土代替黏土作为土工合成材料膨润土垫(GCls)的保护层共同构成垃圾填埋场复合防渗系统的构想。文中选取宁夏银川地区冲-洪积作用形成的天然砾质土料,经人工掺和制配成满足规范对GCls防渗垫保护层渗透系数要求的宽级配砾质土样,在实验室对该土样进行了冻融循环作用下的渗透性能试验研究。结果显示,随着冻融次数的逐渐增加,土样的冻胀率逐渐变大,渗透系数也相应增大,经过12次冻融循环后,渗透系数约增大1～2个数量级;冻融循环初期,冻融作用对土样的影响最为剧烈,随着冻融循环次数的增加以及时间的延续,土样性状逐渐趋于稳定。由于宽级配砾质土对冻融循环作用的敏感性小于粉质黏性土,故采用宽级配砾质土作为Cls/GM的保护层共同组成填埋场复合防渗系统是值得期待的。 相似文献
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Hydraulic conductivity is a dominant parameter in the design of engineered waste disposal facilities such as landfill liners and covers, lagoon liners and slurry walls. It is of interest to a geotechnical or geo-environmental engineer to develop a predictive method of determining the hydraulic conductivity of fine-grained soils, in order to assess its suitability as a liner material. To predict the hydraulic conductivity of soils, researchers and geotechnical engineers have attempted to correlate it with index properties of the soils, such as the liquid limit, void ratio and specific surface. Based on the present study a predictive method has been developed in this paper to predict the hydraulic conductivity in terms of void ratio and shrinkage index (Liquid limit – shrinkage limit) for remoulded fine-grained soils. Though the initial conditions for the soil will affect the hydraulic conductivity behaviour to some extent, both the void ratio and soil characteristics are primary factors in affecting the hydraulic conductivity. Therefore for predictive purpose, the study of hydraulic conductivity behaviour of remoulded fine-grained soils as presented in this paper can be found to be useful for compacted soils also. 相似文献
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Sorption capacity on lead,copper and zinc by clay soils from South Wales,United Kingdom 总被引：2，自引：0，他引：2
The sorption capacity of five clay soils from South Wales in the United Kingdom was investigated using two main tests; physico-chemical and batch equilibrium (BET). The physico-chemical property results show that soil weathered mudrocks (MR1), glacial till (GT1), and estuarine alluviums (NEA4, PEA3 and CEA3) are capable of being used as landfill liners and are chosen for further sorption tests. The batch tests (i.e. sorption tests) on soil suspension produce adsorption-pH curves, showing increasing adsorption at higher pH levels. The sorption data are also presented using adsorption isotherm curves and are best fitted using the Langmuir adsorption equation that yields the maximum adsorption capacity of the soils. The sorption capacity of soils are ranked as estuarine alluvium soils>glacial till>weathered mudrocks. Estuarine alluvium soils show a good buffering capacity and high sorption capability compared to glacial till and weathered mudrocks. The study also discovers that the maximum sorption capacities are highly influenced by the chemical properties of the soils. 相似文献
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Preventing the penetration of rainwater into a landfill site is the main purpose of the final cover in landfill sites. Conventional designs of landfill covers use geotextiles, such as geomembrane and geosynthetic clay liners, and clay liners to lower the permeability of the final cover of landfill sites. However, differential settlement and climatic effects in landfill sites instigate crack development or structural damage inside the final cover. This study therefore investigates the field applicability of a self-recovering sustainable liner (SRSL) as an alternative to the landfill final cover. The SRSL utilizes the precipitation reaction of two chemical materials to form precipitates that fill the pores and thereby lower the overall permeability of the liner. To examine the field applicability of the SRSL system, uniaxial compression tests and laboratory hydraulic conductivity tests were performed under various climatic effects such as wet/dry and freeze/thaw processes. Furthermore, field-scale hydraulic conductivity tests were performed with intentionally induced cracks to demonstrate the self-recovery performance for practical applications. Extensive laboratory and field test results confirmed the capability of the SRSL final cover system to fulfill the strength and hydraulic conductivity requirements, even in harsh field conditions. 相似文献
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Over the last decade, waste disposal has become a particularly sensitive issue in Algeria. New legislation concerning landfill
liner design has been adopted. Traditional methods of landfill liner characterization involve soil sampling and chemical analysis,
which are costly, destructive and time-consuming. New techniques are currently being investigated that aim to provide nondestructive
liner characterisation. This paper details technical aspects associated with electrical conductivity measurements within landfill
liners and presents experimental work to show the direct application of electrical techniques to track ionic movement through
a sand bentonite liner under chemically induced flow. Samples of sand bentonite were mixed and compacted with NaCl electrolytes
at different concentrations. The electrical conductivities of compacted specimens were measured with a two-electrode cell.
The effects of frequency and electrolyte concentration on the conductivity measurement were explored. The relationship between
the soil electrical conductivity and the NaCl electrolyte concentration in interstitial pore fluid was determined. The conductivity
measurements were used to quantify the pore fluid concentration and effective diffusion coefficient of sand bentonite liners.
It is concluded here that the electrical conductivity of compacted specimens depends mainly on the salt concentration in the
pore fluid, and that this approach could therefore be used to track ionic movement through liners during diffusion. 相似文献
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建立系列模拟实验研究了冻融作用对垃圾填埋场防渗层防渗和去污性能的影响。实验结果表明：冻融作用对垃圾填埋场防渗层有一定的破坏作用,对渗透系数和污染物的去除能力均有重要影响;冻融前的渗透系数均低于国家标准（1.0×10-7 cm/s）,冻融后防渗层的渗透系数增加2～6倍;防渗层对COD、Cl-和NH+4的去除率分别从冻融前的68.6%、31.6％和70.5％变为86.2%、18.2％和23.0％。 相似文献
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压实宽级配砾质土干-湿循环效应研究 总被引：1，自引：0，他引：1
为探索在干-湿循环条件下,宽级配砾质土作为垃圾填埋场复合防渗系统中土工织物黏土垫和土工膜（GCLs/GM）防渗衬垫的保护层时其水力特性的变化规律,采用压力膜仪测试了土样干-湿循环作用下的土-水特征曲线参数,并借助van Genuchte方程和Fredlund 3参数方程拟合了0～3次干-湿循环的压实宽级配砾质土样的4条脱湿土-水特征曲线。结果显示：随着干-湿循环次数的增加,试样的土-水特征曲线在0～100 kPa的低吸力区间内逐渐变陡,含水率随吸力增加而逐渐减小,在位于400 kPa附近趋于平缓;干-湿循环过程中,试样的饱和含水率存在峰值,而残余含水率逐渐降低并趋于稳定;两种模型拟合的宽级配砾质土土-水特征曲线的差异不大,van Genuchte模型略优于Fredlund 3参数模型。在此基础上,将试验结果与已有文献中干-湿循环条件下的黏性土以及膨润土的土-水特征曲线进行了比较,表明作为防渗垫保护层的宽级配砾质土更有利于GCLs的吸湿与水化。 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