Laboratory tests of electro-osmotic consolidation combined with vacuum preloading on kaolinite using electrokinetic geosynthetics

Laboratory tests were conducted on kaolinite to investigate the effectiveness of electro-osmotic consolidation combined with vacuum preloading using electrokinetic geosynthetics (EKG). The results showed that the combined method could remove more water and induce larger surface ground settlements compared with the traditional vacuum preloading or electro-osmotic consolidation. Vacuum preloading was quite effective during the first 4?h, though the electro-osmotic consolidation took a main role in dewatering process after 9?h. The combined method could also hinder the development of cracks, induce higher negative pore water pressure and hence increase the efficiency of electro-osmotic consolidation. The results showed that deep electro-osmotic consolidation technique combined with vacuum preloading could result in significant water removal efficiency along with shorter electrode length. Furthermore, both electro-osmotic consolidation and the combined method could consolidate the soil efficiently with low energy consumption.     

土工合成材料在湄洲湾码头工程中的应用

阐述了几种土工合成材料在湄州湾3.5万元t多功能码头中的应用情况,着重介绍了它们的技术性能、施工工艺、质量控制及应用效果。     

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.     

土工合成材料加筋的试验研究

以 6种不同种类的国产土工合成材料为加筋材料 ,即针刺无纺土工织物、涤纶纤维经编土工格栅、玻璃纤维土工格栅、单向塑料拉伸土工格栅、双向塑料拉伸土工格栅和土工网 ,进行三轴试验比较各种土工合成材料对砂的加筋效果 ;进行直剪试验和拉拔试验比较各种土工合成材料与填料 (砂和石灰粉煤灰 )的界面作用特性 ,得到一些有益的结论 ,可指导土工合成材料的优选和研究土工合成材料的加筋机理。     

"土袋"在日本软土地基加固中的应用与分析

近年来,土工合成材料在加筋土工程中得到了广泛的应用,目前常规的设计方法是在土层中水平布设加筋材料,如土工织物、土工网、土工格栅等.介绍了目前在日本应用的一种新的结构形式,即采用加筋材料包裹土体--"土袋"加固软土地基的方法,并从试验和理论两个方面介绍了土袋的加固机理.列举了土袋在日本铁路基床加固、房屋软土地基处理、修筑挡土墙及导流堤坝的应用实例.     

Multifaceted potentials of tire-derived three dimensional geosynthetics in geotechnical applications and their evaluation

Scrapped tire-derived materials, such as tire chips and tire shreds, can be categorized as three dimensional geosynthetics. This paper introduces recent Japanese experience in geotechnical related applications of geosynthetics that focus mainly on tire chips and tire shreds. Three specific applications of tire chips and tire shreds are introduced here. They are: (1) tire shreds to improve drainage; (2) sand-mixed tire chips to mitigate earthquake damage; and (3) tire chips mixed with cement-treated clay to improve toughness and ductility. The developed techniques related to these applications, verification through model testing, as well as element testing and the field applications are presented. It was observed that tire shreds can maintain high permeability even under a high compressive load. When tire chips and/or sand-mixed tire chips are used as a compressible cushion, not only the dynamic load against a structure but also the dynamically induced permanent structural displacement could also be significantly reduced. On the other hand, mixing tire chips with cement-treated clay gives toughness to the geomaterial, and thus provides resistance against the development of cracks during deformation. In addition, an X-ray CT investigation of deformation behavior of such materials demonstrated the success of using cement-treated clay with tire chips as a sealing material to protect leakage of contaminated materials at a waste disposal site in Tokyo bay area.     

土工布在工程实践中的应用

介绍了我国土工布的发展及应用现状,分析了土工布的工程特性,通过工程实践体现了其广阔的应用领域,最后提出其施工要点,从而推广土工布的应用使土工布充分发挥工程价值。     

土工合成材料在公路软基处理中的应用与设计

结合<公路软土地基路堤设计与施工技术规范>和<公路土工合成材料应用技术规范>的规定,对土工合成材料在高等级公路软基处理中的应用设计中应注意的几个问题进行了初步探讨,同时对相关规范的理解和执行提出了建议.     

国内外土工合成材料的发展

土工合成材料是极具生命力的新型土建工程材料 ,其应用已渗透到岩土工程和其它工程建设的各个角落。目前我国正在进行大规模的基础设施建设 ,对其进行研究和开发具有重要的现实意义和深远的历史意义。本文综述了国内外土工合成材料的发展及应用 ,讨论了我国土工合成材料应用和发展方面的差距     

排水与加筋复合型土工合成材料

介绍了一种既能排水又能加筋的新型土工合成材料,该材料可以应用于粘性土加筋土结构,起到减小孔隙水压力、提高稳定性的作用,通过进一步和传统的排水加筋土工材料相比较,阐叙了其排水加筋机理.同时还表述了该材料的各影响因素及其性能,此新型土工合成材料具有较好的应用前景.