Geotechnical analysis of two Nigerian soils for use as clay liners

The cretaceous Auchi shale and the Tertiary Imo shale in SW Nigeria were investigated for their suitability for use as a clay seal in waste disposal landfills. Geotechnical analyses indicated they are highly plastic inorganic clays. Although their geotechnical and chemical properties were within the range suggested by various authors for use as mineral seals, care would need to be taken with the Okada shales as they contain smectite and would be difficult to work and liable to cracking.      

Mechanisms of Leakage through Synthetic Landfill Liner Materials

The introduction of synthetic lining materials for leachate containment and the prevention of groundwater contamination was an important development in landfill technology. These materials have a low hydraulic conductivity which results in minimal leachate release by bulk fluid flow (advection) provided that the barrier (and its construction) is free from defects. However, the effectiveness of these materials as barriers cannot be confirmed unless contaminant release by diffusion is also taken into consideration.
This paper reviews the mechanisms by which transport through barriers occur. It highlights the role of diffusion as a pathway for organic compounds to migrate through synthetic liners and indicates its importance in terms of environmental impact and landfill design.     

《钠基膨润土防水毯》行标的制定

介绍了《钠基膨润土防水毯》标准制定的背景和制定的依据，并对标准中的产品分类、试验项目、实验方法、性能指标等做了详细的阐述。     

污水厂污泥制备垃圾填埋场防渗衬层材料研究

以城市污水厂的污泥复合高岭土用作垃圾填埋场防渗衬层材料，研究了千污泥的掺入量及其颗粒大小、复合土密度、渗滤液性质对污泥复合土渗透性能的影响。结果表明，复合土中污泥的最佳质量分数为40％；提高复合土的干密度可显著降低其渗透系数，当干密度为1.08g／cm^3时复合土的渗透系数达10^-7cm／s数量级，符合垃圾填埋场防渗衬层的要求；渗滤液性质对渗透性能的影响较大，当其电解质浓度较大时复合土的渗透性能随之提高。此外，考察了污泥复合土对重金属的吸附效果，结果表明该复合土可有效吸附垃圾渗滤液中的Cu^2＋、Zn^2＋等重金属。     

膨润土防水毯对回填土密实度的要求

阐述了膨润土防水毯施工中回填土密实度的重要性,介绍了土壤重型击实密度的概念、测试方法和膨润土防水毯对回填土密实度的要求,并提出了回填土的施工要求和技术指导。     

填埋场边坡土工衬垫结构的稳定性分析方法

本文针对现代卫生填埋场典型的防渗衬垫结构,分析了边坡衬垫破坏的原因和形式,结合计算分析了常用土工材料对边坡稳定的影响,并对不同条件下土工材料的选用以及工程设计中的一些注意事项提出了建议。     

钻探工程用粘土矿物材料应用综述

钻探工程是粘土矿物材料的重要应用领域,涉及的粘土矿物品种有蒙脱石、坡缕石、海泡石、高岭石、累托石、水云母、绿泥石等,其中以蒙脱石为主要成分的膨润土用量最大。钻探工程用粘土矿物材料分为水性造浆材料、油性造浆材料、防水堵漏材料、配浆评价土等,其中水性造浆材料占总用量的90%,油性造浆材料在深井、复杂地层钻探工程中应用前景广阔,防水堵漏材料和配浆评价土是粘土矿物材料中的高端产品,防水堵漏材料的复配技术对钻探工程实施有更好的实际价值。     

膨润土防水毯在中海油大厦地下车库防水工程中的应用

介绍了钠基膨润土防水毯在中海油大厦（上海）地下车库防水工程中的应用,包括所选用的Vohex DS钠基膨润土防水毯的主要性能特点和在地下结构中的施工工艺及部分特殊部位如管道穿透部位、预留甩头、侧墙收口的处理方法。     

膨润土防水毯在基础底板防水工程中的应用

膨润土防水毯可广泛应用于市政、公路、水利及民用建筑中,通过首都机场三号航站楼滑行桥下基础底板防水工程,详细介绍了膨润土防水毯的施工工艺,尤其对各特殊节点部位施工进行了详述,保证了工程质量。     

Landfill Lining for Leachate Containment

There is an increasing need for engineered liners to prevent the escape of leachate and to control the migration of landfill gas. This has been influenced by new European and UK legislation and codes of practice.
General principles of site design are explained, followed by a review of the advantages and disadvantages of different liner systems, including mineral liners (natural clay, mudrocks and soil/bentonite admixtures), geomembranes and composite liners.
The need for conservative factors of safety in site design and high standards of quality control, involving full-time supervision and independent certification of the installation works, are considered essential to ensure the effectiveness of the barrier.
There is no one ideal liner material. Composite mineral/geomembrane liners provide the highest degree of security against leakage and, as such, should be considered as 'the norm'rather than for use only in particularly high-risk situations.     

某垃圾填埋场坝基渗透性分析及防治措施

由拟建东港市赤榆垃圾卫生填埋场工程出发,结合该工程建设场地的地质背景条件,通过物探、钻探、压水试验等方法分析了坝基部位的渗透性影响因素,并提出坝基防治措施建议。     

垃圾填埋场渗滤液处理的机理和方法的探讨

近几年来,随着工农业生产的巨大发展和人口的急剧膨胀,垃圾的产生量越来越多.我国垃圾平均增长率达9%以上,超过世界平均增长率（8.42%）.因此垃圾处理是个亟待解决的问题.目前处理城市垃圾固体废弃物的常用方法是填埋法,而垃圾的堆放对周围的环境造成了影响,尤其是对水环境影响更大.很多堆放场产生的垃圾渗滤液严重地污染了地下水质.作者从微生物的角度、土水势的角度和水在多孔介质中渗流的角度,提出了处理垃圾填埋场渗滤液的方法.     

隧道衬砌温度应力的有限元分析

大温差变化对隧道衬砌受力的影响是隧道计算与设计中的一个问题。以武夷山隧道衬砌为例,考虑温度荷载影响,采用有限元法对隧道衬砌结构的变形和受力进行了计算分析,得到了温度应力影响下隧道衬砌和围岩的变形和受力一些规律,此结论可为考虑温度应力影响下隧道衬砌设计与施工提供一定参考价值。     

防渗墙粘土混凝土配合比试验研究

粘土混凝土性能介于塑性混凝土和刚性混凝土之间,具有和易性好、早期强度低、后期强度增长快、抗渗性能好、低弹模和相对较高的强度等特点,是一种理想的防渗墙材料。本文结合山西省米家寨水库除险加固工程粘土混凝土防渗墙试验研究工作,对粘土混凝土原材料选用、配合比设计及其抗渗性能进行研究。     

翻转内衬法在旧燃气管道修复中的应用

介绍了翻转内衬操作系统的清理、内窥检查、下料、混胶及滚胶、翻转吹进、加压固化、端头处理及内衬后的检查等。并针对内衬施工操作中的在翻转过程中压力的调节与翻转速度之间的关系以及内衬完工后 ,影响固化时间的几种因素等技术问题进行了分析 ,探讨了普及推广该技术的意义和在某些方面进行发展的方向     

A linear graphical method to predict the effect of compaction on the hydraulic conductivity of clay liners and covers

It is proposed to present compaction relationships by plotting the inverse of the dry density versus the molding water content. In the proposed graph, the curves for equal degree of saturation become straight lines. The proposed new graph is shown to be very convenient to assess the saturated hydraulic conductivity, k _sat, of non-swelling compacted clay, using a dual porosity model. The value of k _sat depends on the secondary porosity between clay clods. The equation developed for equal k _sat value appears also as a straight line in the proposed graph. It facilitates the prediction of k _sat from field compaction data and thus the prediction of field performance of clay liners and covers.     

Treatment of landfill leachate by the Fenton process

In recent years, studies of leachate treatment by conventional Fenton, photo-Fenton and electro-Fenton processes have indicated that these methods can effectively reduce concentrations of organic contaminants and color. In addition, the process can increase the biodegradable fraction of organic constituents in leachate, particularly in mature or biologically recalcitrant leachate. Oxidation and coagulation both play important roles in the removal of organics. Initial pH, dosages of Fenton reagents, aeration, final pH, reagent addition mode, temperature, and UV irradiation may influence final treatment efficiency. In this paper, current knowledge of performance and economics of Fenton processes for treatment of landfill leachate as reported for laboratory, pilot and full-scale studies is reviewed, with the conclusion that the Fenton process is an important and competitive technology for the treatment or pretreatment of landfill leachate.     

Inhibition and recovery in a fixed microbial film leachate treatment system subject to shock loading of copper and zinc

The impacts of shock loadings of copper and zinc (up to 50 mg l(-1)) on the treatment efficiency of a mesoscale-fixed microbial film landfill leachate treatment system were investigated. Treatment inhibition and recovery were monitored in sequence over two 36 h experimental runs. The fate of added metals was also investigated. Copper, and to a lesser extent zinc, added to the treatment systems accumulated on the biofilm media. Increasing copper inputs (>10 mg l(-1)) progressively inhibited biological treatment of ammoniacal-nitrogen and carbon; this inhibition persisted into the recovery phase for nitrogen but not for carbon. Only the highest input of zinc affected media metal contents and carbon treatment rates; the latter inhibitory effect did not persist into the recovery phase. A small proportion of the metals accumulated on the biofilm media during the inhibition phase was released into the bulk leachate during the recovery experiment. These findings suggest a need to manage metal inputs into leachate treatment systems in order to ensure their continued efficacy.     

Evaluation of interface shear strength of composite liner system and stability analysis for a landfill lining system in Thailand

The paper presents the case history of laboratory evaluation of the interface shear strength properties of various interfaces encountered in a modern day landfill with emphasis on proper simulation of field conditions and subsequent use of these results in the stability analyses of liner system. Over 70 large direct shear tests were systematically conducted to evaluate the interface shear strength properties of composite liner system using project specific materials under site specific conditions, being used at non-hazardous and hazardous landfills project situated in Sa Kaeo Province, Thailand. The critical interfaces were located between the geotextiles and the smooth geomembrane (GM), the smooth GM and the geosynthetic clay liner (GCL), and the smooth GM liner and the compacted clay liner (CCL) with the interface friction angles ranging from 6.5° to 10.5° for dry conditions and 6.5° to 9.5° in wet conditions. The residual shear stress for these interfaces was attained at a displacement less than 4 mm. Three methods, namely, limit equilibrium method (LEM), limit method (LM), and the simple composite column (SCC) approach were used to evaluate the tensile loads induced in the geosynthetic components. The SCC approach proposed by Liu, C.N. [2001. Tension of geosynthetics material regarding soils on landfill liner slopes. Proceedings, National Science Council ROC(A), 25(4), 211–218] that takes into account the force equilibrium as well as displacement compatibility yielded satisfactory results. The factor of safety for geosynthetic components in the liner was found to be greater than 3.0 for both types of landfill.     

泵站流道钢衬底部混凝土浇筑方案

引江济汉工程为南水北调中线一期工程汉江中下游四项治理工程之一。为了保证泵站流道钢衬底部混凝土浇筑的施工质量,本工程在混凝土浇筑中进行了多方面的方案优化。