• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.209-222
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• 1993

This article is a case study of the ground improvement project which was carried out for manmade landfill. The project area is located near to Kapchun, Teajon and composed of the municipal wastes dumped, demolished building debris, coal ash and industrial waste made between 1983 and 1989. The DDC(dynamic deep compaction) based on the results of the test compaction at two representative locations was carried out from March 16, 1992 to Oct. 25, 1992. Field measurements and laboratory tests were carried out for ground improvement assessment and quality control for the DDC(dynamic deep compaction) work. From the results of field measurements and laboratory tests, it was found that the DDC work was successful: waste landfill was compressed considerably (${\fallingdotseq}$ 15% of full depth); and the strength was increased satisfactorily (${\fallingdotseq}$ 100% of original penetration resistance), Also, it is expected that the results of this work could be a guide to the future DDC work with the similar ground conditions, i.e. man-made landfills.

• Advanced Composite Materials
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• v.17 no.3
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• pp.235-246
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• 2008

This paper is concerned with geotextiles bonded chemically with geogrid to form a geocomposite. Geotextiles, thermally bonded and non-woven, play an important role as a separator. Also, this study investigates the resistance to the application environment of geotextile composites. Here, numerous tests have been performed and it was revealed from experimental results that thermally bonded geotextile in geosynthetic composites showed superior characteristics to that manufactured from needle punched non-woven method in terms of tensile strength, tensile strain and high separation performance. It was noted from experiments that the geotextile prepared for separation purpose and manufactured in a thermal bonding method showed relatively low permittivity so that it could be used as a smooth separator. In addition, PVA geotextile/HDPE geomembrane composites were designed and manufactured to investigate the waste landfill related properties. Numerous experiments have been performed and experimental results were summarized to evaluate practical applicability of PVA geotextile/HDPE geomembrane composites. Among the properties of proposed geomembrane composites, evaluation has been focused on the investigation of mechanical properties, AOS (apparent opening size), permittivity and ultraviolet stability.

• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.75-83
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• 2000

Recently, many landfills are constructed by using geosynthetics with earth materials. Geotextiles in geosynthetics are applied for the various purposes such as filters of the leachate collection and removal system and protectors of geomembrane liner. However geotextiles can be exposed to direct sunlight during the construction of landfill for several months. As you know the exposure of polymers to sunlight can be a major source of degradation of them. This study is to suggest a criteria on the installation of heavy weight geotextiles at the landfill. For this purpose, several different geotextiles were evaluated by outdoor exposure at two different locations and under the different seasons for one and half years. As the results of outdoor exposure, polypropylene geotextiles with 500g/$m^2$ and 700g/$\textrm{m}^2$were maintained around 40% of the initial strength during for one and half years. However, the polypropylene geotextile of 1000g/$\textrm{m}^2$showed 65% of the retained strength for the same duration of exposure. The retained strength of all polypropylene geotextile reduced dramatically with the cumulative sunshine radiation on a horizontal surface of around 1500MJ/$\textrm{m}^2$.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.97-106
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• 2007

In this study, experiments are conducted to find out the effect of waste leachate on landfill clay liner system. Tensile test, hydrometer analysis and crack pattern test were conducted on sand-bentonite mixtures with different pH values of water. The tensile strength of specimen compacted with pH 9 of water is smaller than that of specimen compacted with for pH 3 and 6 of water. That is, the higher the pH value, the smaller the tensile strength, because a higher pH solution decreases flocculation phenomenon. The percent finer also increased with high pH value in particle size distribution of fine grained soil (<0.075 mm), because the velocity of particles settling decreases. This trend becomes the clearer as the content of bentonite, becomes the larger, because the higher pH value decreases flocculation structure of fine soils. The results of the crack pattern tests also showed the effect of pH values of water.

• Journal of the Korean Geotechnical Society
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• v.34 no.3
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• pp.43-56
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• 2018

Vertical cutoff walls such as steel pipe sheet piles (SPSPs) have been commonly applied for the construction of the offshore waste landfill site. Because the SPSPs are sequentially installed by connecting their joints to those of adjacent piles, their mechanical stability should be ensured against the inherent external forces on the sea. The objective of this study is to evaluate the structural performances of the newly developed types of SPSP joint compared with those of other joint types. The problems of the traditional SPSP joints are investigated, and an advanced joint shape of SPSP, which is named double H with L-T (DHLT) joint, are designed for improving the constructability and maintenance. Full-scale models of the DHLT joint are manufactured, and then its joint areas are filled with grout material. After 28 days of curing time, compressive and tensile strength tests were performed on the joint models and the test results were compared with those of the traditional joints. Experimental results show that the structural capacities of the DHLT joint models are lower than those of traditional joints due to the influence of grout and steel members. In the cases of the compressive strength test, especially, bending occurs on steel H-beam with no distinct cracks in grout due to the asymmetrical structure of joint which has no reaction force. This study shows that the performance of the SPSP joint can be improved by considering the influence factors on the structural capacities estimated by the experimental tests.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.5
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• pp.132-144
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• 2001

Iln order to figure out criteria of bentonite for using as impervious material of waste landfill, laboratory experiments were performed to reveal the geotechnical properties of soil-bentonite mixtures such as compaction test, direct shear test, unconfined compression test, triaxial compression test, consolidation test and permeability test. The results of the study are summarized as follows ; 1. Based on the compaction test, optimum moisture content increased with the increase of bentonite content, but maximum dry density decreased. 2. In unconfined compression test, the maximum strength of the soil-bentonite mixtures appeared at 10% bentonite content. The correlation equation between stress($\sigma$) and strain($\varepsilon$) of the soil-bentonite mixtures is given by ; $\sigma=\frac{a\cdot\varepsilon}{\varepsilon^n+b}$ 3. In shear test of the mixtures. the shear strength showed an increasing trend with increase of bentonite content and the maximum shear strength appeared at 10% bentonite content. 4. In consolidation test, the coefficient of compressibility $(a_v)$$(m_v)$$(C_v)$

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.607-614
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• 2000

Settlement with crack on the hardened liners may occur in the weak clay due to waste load since the stiffness of the hardened liner is greater than that of the clay layers. Way of reducing deformation crack in the hardened liner is investigated using two computer programs, CONSOL and FLAC. The computer program CONSOL estimates the magnitude of settlement with time in clay layers and FLAC analyses the stress and deformation relationship between the foundation of landfill and waste load. The results show that a representative block of the analyzed area reaches the consolidation settlement of 1.32m, 8.8 years after the disposal of waste started with the degree of consolidation U=90%. The stress within the hardened liner exceeds the allowable vertical stress of 5kg/$\textrm{cm}^2$ and horizontal stress of 1.67kg/$\textrm{cm}^2$ at the concave part of the liner where the main and branch drainage pipes of leachate are located. It was recognized that the thickness of the interested area should be enlarged or the strength of the same area should be improved to tolerate the planned waste load.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.589-594
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• 2006

The recycling of industrial wastes in the concrete manufacturing is of increasing interest worldwide, due to the high environmental impact of the cement and concrete industries and to the rising demand of infrastructures, both in industrialized and developing countries. The production of municipal wastes in the South Korea is estimated at about 49,902 ton per day and only 14.5% of these are incinerated and principally disposed of in landfill. These quantities will increase considerably with the growth of municipal waste production, the progressive closing of landfill, so the disposal of municipal solid waste incinerator(MSWI) ashes has become a continuous and significant issue facing society, both environmentally and economically. MSWI ash is the residue from waste combustion processes at temperature between $850^{\circ}C\;and\;1,000^{\circ}C$. And the main components of MSWI ash are $SiO_2,\;CaO\;and\;Al_2O_3$. The aim of this study is to find a way to useful application of MSWI ash(after treatment) as a structural material and to investigates the hydraulic activity, compressive strength development composition variation of such alkali-activated MSWI ashes concrete. And it was found that early cement hydration, followed by the breakdown and dissolving of the MSWI-ashes, enhanced the formation of calcium silicate hydrates(C-S-H). The XRD and SEM-EDS results indicate that, both the hydration degree and strength development are closely connected with a curing condition and a alkali-activator. Compressive strengths with values in the 40.5 MPa were obtained after curing the activated MSWI ashes with NaOH+water glass at $90^{\circ}C$.

• Advances in environmental research
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• v.10 no.1
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• pp.59-86
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• 2021

Landfilling is the most commonly adopted method for a large quantity of waste disposal. But, the main concern related to landfills is the generation of leachate. The leachate is high strength wastewater that is usually characterized by the presence of high molecular recalcitrant organics. Several conventional methods are adopted for leachate treatment. However, these methods are only suitable for young leachate, having high biodegradability and low toxicity levels. The mature and stabilized leachate needs advanced technologies for its effective treatment. Advanced oxidation processes (AOPs) are very suitable for such complex wastewater treatment as reported in the literature. After going through the literature survey, it can be concluded that Fenton-based approaches are effective for the treatment of various high/low strength wastewaters treatment. The applications of the Fenton-based approaches are widely adopted and well recognized due to their simplicity, cost-effectiveness, and reliability for the reduction of high chemical oxygen demand (COD) as reported in several studies. Besides, the process is relatively economical due to fewer chemical, non-sophisticated instruments, and low energy requirements. In this review, the conventional and advanced Fenton's approaches are explained with their detailed reaction mechanisms and applications for landfill leachate treatment. The effect of influencing factors like pH, the dosage of chemicals, nature of reaction matrix, and reagent ratio on the treatment efficiencies are also emphasized. Furthermore, the discussion regarding the reduction of chemical oxygen demand (COD) and color, increase in biodegradability, removal of humic acids from leachate, combined processes, and the pre/post-treatment options are highlighted. The scope of future studies is summarized to attain sustainable solutions for restrictions associated with these methods for effective leachate treatment.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.335-341
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• 2015

Various display devices has been increasing also using waste LCD glass in accordance with the used developed, because circumstances that are most landfill or incineration, are needed research on recycling measure of the using waste LCD glass. Therefore, in this study, to try to assess the basic mechanical properties of concrete mixed with using waste LCD glass micropowder through the room mixed test. According to the study results, the more replacement rate increases, the characteristics of the concrete showed a tendency to decrease slightly. However, according to the small value, it is expected to improve the advanced experimental values by refining the grain size of the materials used to be processed into spheres.