关于JG／T193—2006（《钠基膨润土防水毯》有关问题的讨论

对建材行业标准JG／T193—2006《钠基膨润土防水毯》中有关膨润土的诸如标准的制定、标准的命名、膨润土吸蓝量、钠基膨润土、人工钠基膨润土的变质以及膨润土的耐久性等一些有争议的问题进行了讨论,并就有关膨润土防水毯国家标准的编制提出了一些建议。     

膨润土防水毯的研制及其在垃圾填埋场中的应用

在简单介绍膨润土材料的性能特点、防水机理和作为防水材料的发展历史的基础上，着重介绍膨润土防水毯(GCL)的研制过程及其主要技术指标，并对生产和使用中需要关注的问题进行讨论。结合垃圾填埋场对防渗材料要求的分析，介绍膨润土防水毯在垃圾填埋场中的应用方法。     

膨润土防水毯应用若干问题探讨

对膨润土防水毯应用中业界争论较多的几个问题,以实验理论数据和工程实际效果为依据,进行了探讨,如:人工钠化膨润土能否应用,膨润土防水毯在提前水化的状态下如何继续保持其防水功效,防水毯是否需要施做保护层,单位面积质量和渗透系数的关系,以及膨润土防水技术的发展方向,等等。     

膨润土防水毯应用若干问题谈

分析了膨润土防水毯应用中存在的一些问题，介绍了区分天然钠基膨润土与人工钠基膨润土的方法以及地下工程采用膨润土防水毡进行防水的设计施工要求。     

膨润土防水毯在水利工程中的应用

介绍了钠基膨润土防水毯的优点,通过水利工程中底部防渗处理对钠基膨润土防水毯应用的工程总结,提出了对水利工程中钠基膨润土防水毯施工的几点建议。     

膨润土防水毯及其在地下防水工程中的应用

介绍了膨润土防水毯的防水原理、特性和施工工艺,并举例说明了膨润土防水毯在地下防水工程中的应用。     

膨润土防水毯在地下室防水工程中的使用

阐述膨润土防水毯的特点,结合工程实例对膨润土防水毯在地下室防水工程中的使用进行了的探讨。     

福州档案馆新馆人工湖工程防水技术

介绍了福州档案馆新馆人工湖防水工程应用LAKEMAT誖膨润土防水毯的防水施工技术,阐述了人工湖基面处理、膨润土防水毯材料准备事项,以及自然放坡驳岸与室内水系的防水施工工艺、膨润土防水毯搭接与固定、斜坡管道穿透位置防水处理等重要环节。     

膨润土防水毯在南京地铁车站施工中的应用

以南京地铁二号线一期工程向兴路站施工为例,详细介绍了膨润土防水毯的施工工艺和具体操作方法,指出了膨润土防水毯铺设施工过程中的注意事项,并阐述了膨润土防水毯的实际效果,从而为类似工程积累施工经验。     

膨润土防水毯搭接方式渗流特性试验研究

为了从渗流量和渗透稳定角度深入研究膨润土防水毯搭接处的防渗问题,开发了由压力控制系统和模型试验系统两部分组成的具有施加法向应力作用的接触面渗流试验装置,建立了真实模拟设计提出的防水毯铺设工序的渗流搭接物理试验方法,并通过不同工况下的膨润土防水毯搭接渗流试验,初步探讨了搭接处膨润土发挥防渗作用的最佳状态。结果表明:防水毯的搭接宽度宜大于30 cm;搭接处的膨润土添加量最好在4000~5000 g/m2之间选取;取防水毯规格型号为5000 g/m2能满足防渗体的要求;围压大小和加载路径对搭接处的渗透性影响均较大,若围压先增大然后再减小,搭接处仍能保持较为密实,其渗透性变化不大。     

The impact of mining solutions/liquors on geosynthetics

Mine owners and operators are presented today with a diverse range of geosynthetic products which all appear to provide similar benefits. Key factors in selecting geosynthetics for use in the mining industry include construction and operational durability issues such as slope stability, puncture resistance and resistance to weathering; but also their chemical resistance when they come into contact with the extreme liquors present on many mining operations and processes. The long-term performance of the geosynthetic depends largely on the type of polymer used in the manufacture, or in the case of geosynthetic clay liners (GCLs), also on the mineralogy and chemical make of the bentonite present in the GCL. This paper provides a guide to the characteristics of the leachates/liquors likely to be generated for a given mining process and the likely effect it will have on the performance of a given geosynthetic.     

Effect of water salinity on the water retention curve of geosynthetic clay liners

The effect of water salinity on the water retention curve of geosynthetic clay liners (GCLs), under constant volume condition is examined. The results indicate that at a constant gravimetric moisture content the total suction increases as the salinity of the wetting liquid increases. Furthermore, the difference in total suction between the GCL hydrated by saline water and distilled water is greater than the difference in the osmotic potential of the wetting water. This behaviour is possibly caused by the matric suction being affected by the expected chemically induced pore size change of the bentonite component of the GCL.     

膨润土防水毯在渗滤液环境下防渗性能的测试应用研究

膨润土防水毯作为一种优异的防渗材料,国内暂无其在渗滤液环境下的渗透性能报道。本文拟配置性能组分稳定的代表性合成渗滤液作为实际渗滤液的替代试验介质,研究合成渗沥液对膨润土原料膨胀性能和滤失性能的影响,测试在合成渗滤液环境中,不同压力和温度条件下膨润土防水毯的渗透系数,以此为垃圾填埋工程和其他固废填埋工程使用膨润土防水毯作为防渗衬垫提供指导。     

Seismic performance and numerical simulation of earth-fill dam with geosynthetic clay liner in shaking table test

In this paper, shaking table tests were carried out on both a small-scale and a full-scale earth-fill dams with geosynthetic clay liners to examine their seismic performance. The behavior of these fully instrumented earth-fill dams when subjected to seismic loading was also simulated by numerical analysis. Firstly, in the small-scale shaking table test, no failure was observed along the geosynthetic clay liner when the earth-fill dam was subjected to seismic motion. Numerical analysis confirmed that the behavior of the model earth-fill dam was unaffected by the geosynthetic clay liner. Secondly, a comparative shaking table test was carried out on full-scale earth-fill dams, one with a sloping core zone and another with a geosynthetic clay liner. Both model dams showed similar acceleration response and deformation behavior. It should be mentioned that the acceleration response increased gradually toward the top of the dam, and the deformation, after shaking, was relatively large near the foot of the slope. These observations were successfully simulated by the numerical analysis.     

Design and placement considerations for clay and composite clay/geomembrane landfill final covers

The performance of clay and clay geosynthetic combinations for landfill barrier layers has not always proved predictable and the integration of geosynthetic materials into conventional landfill designs presents some interesting problems which were previously unforeseen.

This paper looks at identifying and mapping the approach to some specific considerations for clay and geomembrane/clay barriers. These considerations include: long-term performance of clay barriers, short-term and long-term stability of clay barriers, clay/geomembrane interface behavior, and the phenomena of moisture build-up beneath exposed membrane liners.     

我国四类衬垫系统防污性能的比较分析

对我国填埋场采用的四类衬垫进行了防污性能的比较分析。评价参数包括渗漏率、污染物击穿时间及衬垫系统底部浓度值。除了2m压实黏土衬垫(CCL)外,其余3种均为包含土工膜(GM)的复合衬垫。分析模型采用了污染物通过有缺陷膜复合衬垫的一维运移解析解。以镉离子(Cd2+)为渗滤液中重金属离子的代表;以苯为其中挥发性有机污染物的代表。研究表明土工复合膨润土垫(GCL)复合衬垫的渗漏率最小,2m黏土最大,两者的差别可在3～5个数量级。GCL复合衬垫对重金属离子具有较好的防污性能,尤其是在高水头及复合衬垫接触较差的情形。厚度较大的2m黏土对挥发性有机污染物的防污性能较好,其击穿时间要比GCL复合衬垫大2～3个数量级。随着水头的增大,CCL复合衬垫的防污性能逐渐地优于2m黏土。在10m水头作用下,CCL复合衬垫底部的100年浓度可比2m黏土小近一个量级。单层膜衬垫的防污性能较差,不适合作为填埋场的衬垫系统。控制填埋场复合衬垫的施工质量和渗滤液水头尤为重要。     

关于膨润土防水毯防渗性能及稳定性的影响因素分析

总结了钠基膨润土防水毯（GCL）的防渗机理,从膨润土质量特性、渗透液水质、干湿循环、冻融循环等方面对GCL防渗性能及服务期稳定性的影响因素进行了论述,希望对改善防水毯性能研究提供参考。     

Insufficient initial hydration of GCLs from some subgrades: Factors and causes

Water retention and hydration tests are reported for three needle punched geosynthetic clay liners (GCLs). GCLs hydration and their maximum hydration capacity were assessed against subgrade soils prepared at different initial gravimetric water contents. The subgrade soil mineralogy and particle size distribution, as well as the carrier geotextiles used in GCLs, are shown to have a significant impact on the GCLs hydration behaviour. This work highlights the need to consider the unsaturated properties of both the GCLs and the subgrade soil when assessing the hydration of the GCLs. At gravimetric water contents above the GCL water entry value (≈30%), some forms of GCL configuration may be better than others with respect to ability to hydrate from a given soil. However, the partial hydration of GCL is mostly controlled by the bentonite microstructure for gravimetric water contents below the water entry value of the GCLs.     

Hydraulic Conductivity of Nonprehydrated Geosynthetic Clay Liners Permeated with Inorganic Solutions and Waste Leachates

To investigate systematically the effects of electrolytic solutions on the barrier performance of geosynthetic clay liners (GCLs), a long-term hydraulic conductivity test for 3 years at longest was conducted on a nonprehydrated GCL permeated with inorganic chemical solutions. The hydraulic conductivity test for waste leachates was also conducted. The results of the test show that the hydraulic conductivity of GCLs significantly correlates with the swelling capacity of bentonite contained in GCLs. GCLs have excellent barrier performance of k<1.0×10^-8 cm/s when the free swell is larger than 15 mL/2 g-solid regardless of the type and concentration of the permeant solution. In addition, when the results of the hydraulic conductivity test with chemical inorganic solutions were compared to those with waste leachates, the hydraulic conductivity of GCL permeated with chemical solution was almost the same within the electric conductivity of 0-25 S/m as that permeated with waste leachate having similar electric conductivity. The hydraulic conductivity of GCLs to be used in landfill bottom liners can be estimated by the hydraulic conductivity values obtained from the experiment using chemical solutions having the similar electric conductivity values, if the chemical solution had the electric conductivity within=25 S/m.