Case histories of landfill erosion protection using geosynthetics

This paper presents case histories of geosynthetics installed for erosion control at solid waste landfills. A case history of a successful application at a landfill in Ohio is discussed, along with a less successful application at a landfill in Missouri. The erosion process and typical design standards employed at modern landfills to mitigate the effects of erosion are discussed. Discussion of an ongoing research project and recommendations conclude the paper.     

土工合成材料在软土路堤中的应用

讨论了在软土地基上填筑高路堤时应用土工合成材料处理的作用原理，通过有限元结合圆弧法理论对铺设土工材料后的路堤进行稳定分析，比较了是否铺设土工材料时地基的变形情况，介绍了铺设土工材料的施工技术，并通过工程实践，验证了应用的可行性。     

Effects of sediment bulk properties on erosion rates

Considerable work has been done recently on the effects of sediment bulk properties on erosion rates. From this it is known that erosion rates depend on at least the following parameters: bulk density, average particle size, particle size distribution, mineralogy, organic content, volume of gas in the sediment, salinity of the pore waters, and time after deposition. This work is reviewed and discussed here with the purpose of presenting a quantitative overview of the effects of each of these parameters. This information is then used to demonstrate a procedure for estimating erosion rates of sediments based on a knowledge of their bulk properties.     

The erosion behaviour of biologically active sewer sediment deposits: observations from a laboratory study

The erosion behaviour of various fine-grained sediment deposits has been investigated in laboratory experiments. This work mainly focused on tests using sewer sediment in which strong biochemical reactions were observed during the deposit formation period. A small number of initial tests were conducted in which the deposits were made from mixtures of “clean” mineral and organic sediments. The erosion behaviour observed in these tests was compared with the erosion characteristics for sediments taken from deposits in a sewer. The impact of the biological processes on physical properties such as bulk density, water content, deposit structure and the erosive behaviour as a function of bed shear stress are quantified and discussed. Based on these observations it is believed that bio-processes weaken the strength of the in-pipe sediment deposits. A significantly weaker sediment surface layer was observed during deposition under quiescent oxygen-rich conditions. This resulted in a deposit with low shear strength which may be a cause of a first foul flush of suspended sediment when flow rates were increased. Comparison between tests with sewer sediments and the artificial representative surrogates suggested that the deposits of the later did not correctly simulate the depositional development and the resultant erosion patterns observed with the more bio-active sewer sediment.     

土工合成材料在沥青路面施工中的应用

指出了目前沥青混凝土路面存在的突出问题以及采用改性沥青和SMA技术解决这些问题时存在的不足,介绍了采用土工合成材料引入沥青混凝土路面的优点及其在施工中的应用情况,收到了显著的经济效果。     

Sequential erosion/deposition experiments--demonstrating the effects of depositional history on sediment erosion.

Experiments on the erosion of a bed of kaolinite were carried out in a rotating circular flume. Each experiment was carried out using the stratified bed which resulted from the previous experiment. Changes in suspended sediment concentrations during the experiments were explained by the history of the deposition. The sequence of experiments showed how the rate of erosion and the amount eroded reflected the structure of the bed and that of the individual flocs which created it. Results suggest that modelling of sediment/contaminant transport needs to account for the manner in which deposition took place.     

土工合成材料在路面病害处理中的应用

结合石安高速公路中修罩面时病害处理工程实践,介绍了无纺土工布和玻纤网两种土工合成材料的特性和施工工艺,得出了土工合成材料作为沥青面层增强材料能改变路面应力分布,防止裂缝产生,提高路面整体强度的结论。     

An overview of active and hybrid structural control research in the U.S.

Under the leadership of the U.S. National Science Foundation in forming the U.S. Panel on Structural Control Research and in launching a program initiative in the area of structural control, there has been a surge of interest in this research field. Recent progress in active and hybrid control research in the U.S. is summarized in this paper. Some areas of research needs are identified and possible future directions for research and development in active and hybrid control are commented upon.     

Studies of metropolitan development: An overview

This short paper highlights certain findings from some recent studies concerning metropolitan development in the industrialized world. Two particular aspects are stressed: (1) a shift in thinking from city systems conceived as subnational hierarchies of centres to city systems conceived as elemental nodes in various international networks facilitating logistical processes of exchange, and (2) the need to enhance our primitive understanding of interacting metropolitan change processes which are operating at significantly different speeds. These two issues are briefly addressed amidst some introductory remarks about the six related papers which follow in this special issue.     

Organic micropollutants in drinking water: An overview

Biological contamination is still the most significant public health risk from drinking water even in industrialized countries. High potential for organic chemical transport to drinking water continues to exist even with source protection because of the multitude of chemical types and quantities. Drinking water is usually not a unique source nor the most significant contributor to total exposure from synthetic organic chemicals but it might be one of the most controllable.The major public concern with drinking water contamination has been possible contribution to cancer risks from organic micropollutants. Even though the actual risks are probably small in most cases it is clearly within the public interest to prevent adulteration of water supplies and to protect their quality for the future so that these concerns or risks can be avoided.A risk assessment/management decision model is suggested which may assist the process of making rational assessments of these contamination problems and control decisions that consciously consider all of the available data in a consistent manner.     

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.     

Drainage principles and the use of geosynthetics

Drainage is defined as the process of transporting liquid from one location to another. The focus of this paper is to examine basic subsurface drainage principles, and demonstrate how and why liquids are effectively transported from one location to another using geosynthetic materials in place of traditional construction materials.     

道路边坡稳定性及水土流失治理问题分析

分析了道路边坡稳定性及水土流失治理问题,从土体加固、坡面防护、排水措施三方面介绍了道路边坡水土流失治理措施,能够更好地保证道路边坡的稳定性,并对水土流失问题进行妥善解决。     

谈综合车间土工合成材料地基的施工技术

介绍了土工合成材料地基处理的施工技术措施和要求 ,并就土工合成材料地基工程质量的验收标准及强度测试结果作了阐述 ,提出了复合垫层施工时应注意的具体问题。     

土工合成材料在沥青路面施工和养护工程中的应用

介绍了沥青路面的优点,简述了土工合成材料的主要品种和特性,并从土工合成材料的选择、施工工序和基本要求等方面,阐述了土工合成材料在沥青路面施工中的应用,指出使用土工合成材料能有效遏制路面裂缝的产生,证明了土工合成材料在道路补强工程中的优异性能。     

挤扩多支盘钻孔灌注桩孔底沉渣厚度的控制

分析挤扩多支盘钻孔灌注桩施工中影响孔底沉渣的主要原因,介绍实际施工中沉渣厚度的检测方法,提出控制挤扩多支盘钻孔灌注桩孔底沉渣厚度的具体方法。     

屋面与光伏技术综述

简介在过去30年的大部分时间里,太阳能技术在建筑物上应用的标准做法是把晶体硅太阳能板安装在架子上.如今一种名叫薄膜光伏的新技术改变了太阳能收集器在建筑物上的安装方法.本文将介绍这2种新旧太阳能技术以及光伏系统设计和安装方面的知识.