• Journal of the Korean GEO-environmental Society
• /
• v.6 no.4
• /
• pp.13-26
• /
• 2005

In this study, research results on organic and inorganic pollutant migration through single and composite liner were summarized. On the basis of these summarized research results, a design program for landfill liner, which can be used to optimize the liner thickness based on the allowable ground water criteria around the landfill subsurface, was developed. A reasonable liner thickness was obtained from the program output results, in the case of the migration of $Cl^-$ ion through a single clay liner. Therefore, the developed program could be used to carry out a preliminary design for landfill liners with respect to organic and inorganic pollutants.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2022.10a
• /
• pp.345-346
• /
• 2022

본 논문에서는 유류오염사고 발생에 의해 지반 내에 오염물이 유출되었을 때, 오염물 확산방지를 목적으로 차수재의 차수성능 평가를 위한 수치해석을 수행하였다. 해석결과, 차수재의 차수효과에 의해 동일한 투수계수 및 관측위치 조건에서 오염물 접촉시간 경과에 따른 농도가 크게 감소한 것을 확인하였다.

• Geotechnical Engineering
• /
• v.14 no.5
• /
• pp.191-204
• /
• 1998

The feasibility of fly ash was evaluated as an alternative liner material to the conventional clay liner of landfills through modeling and laboratory experiments. In order to consider the effect of unsaturation on water flow through the liner, analyses were made to compare flow characteristics in saturated liner with that of unsaturated one. Contaminant migration characteristics in liners were investigated by batch experiment and modeling, in which phenol was employed as a model was solved by numerical techniques of finite difference method and predictor-corrector method to deal with high non-linearity. Sequential method was used to handle the system of differential equations. Results show that the alternative liner material is more capable of cutting off water flow in unsaturated condition and in preventing phenol from passing through it. It can be seen that, under the flow conditions considered in this study, the conventional saturation approach underestimates the amount of water passing through the liner and doers the cut-off capability against phenol significantly.

• Proceedings of the KSEEG Conference
• /
• 1999.04a
• /
• pp.282-284
• /
• 1999

• Journal of the Korean Geotechnical Society
• /
• v.19 no.2
• /
• pp.87-95
• /
• 2003

In this paper, the discrete element method was applied to evaluate the stability of composite cover and lining system of landfill. This method is capable of estimating the distribution of tensile force and shear stress mobilized in each liner component and its interfaces, based on a relationship of force and displacement. It was assumed that the cover soil and geomembrane were comprised of slices connected with elastoplastic Winkler springs and tensile spring respectively. Parametric study using this method was performed and compared with other techniques based on limit equilibrium method fur the example analysis.

• Geotechnical Engineering
• /
• v.13 no.4
• /
• pp.5-12
• /
• 1997

The potentiality of water treatment sludge as the alternative liner and cover materials in landfills is investigated. A series of tests were performed on sludge admixtures to examine their compaction, compressive strength, leaching, hydraulic conductivity characterisit its and the compatibility with representative leachate within landfills. Results from the tests show that low hydraulic conductivity can berachieved with sufficient stabilizer contents and curing. It is recognized that the hydrauac conductivity decreases with increasing bentonite content and the percentage of bentonite needed to make the hydrauic conductivity below 1$\times$10-7cm/ sec was 40% for water treatment sludge. It was found that the effect of the municipal waste leachate on the hydraulic conductivity of the admixtures is negligible.

• Journal of Soil and Groundwater Environment
• /
• v.7 no.1
• /
• pp.41-51
• /
• 2002

Recently, domestic waste landfills are constructed sometimes on seashore area to provide large landfill area. In order to strengthen the foundation of landfills and to prevent the infiltration of leachate through the bottom, many cases of constructing cement hardened liners on seashore clays are found. In these cases, it is possible to have cracks in the hardened liners due to settlement with waste load since the stiffness of the hardened liner Is greater than that of clay liners. In this study, the capability of Self-Sealing and Self-Healing (SSSH) liner made with a seashore clay in the metropolitan landfill to prevent the percolation of water and leachate is examined using flexible-wall permeameter test and using uniaxial compression test. Applicability of SSSH to weathered granitic soil is also examined for self-sealing capabilities. The result of Flexible permeameter test for SSSH with the seashore clay showed that permeability obtained was lower than permeability criteria of Korean waste management law. The permeability and strength characteristics of SSSH with granitic soil and bentonite showed better results than with the seashore clay.

• Journal of Soil and Groundwater Environment
• /
• v.6 no.3
• /
• pp.53-59
• /
• 2001

There is a lot of method to manage the insanitary landfill but vertical cutoff walls have been widespreadly used and were installed into the subsurface to act as a barrier to horizontal groundwater flow, The stabilized material such as specialized cement or mixed soil with additives has been generally applied for the materials of the deep soil mixing barrier in korea. The amount of the stabilized material is dependent on the field conditions, because the mixing ratio of the material and the field soil should achieve a requirement in the coefficient of permeability, lower than 1.0$\times$$10^{7}$cm/sec. This study determined the quantity and optimized function ratio of the stabilized material in the formation process of the mixed barrier that was added with stabilized material on the field soil classified into SW-SC under USCS (Unified Soil Classification System). After that the fly ash and lime were selected as an additives an that could improve the function of the stabilized material and then the method to improve the functional progress in the usage of putting into the stabilized material as an appropriate ratio was studied and reviewed. The author used the flexible-wall permeameter for measuring the permeability and unconfined compressive strength tester for compressive strength, and in the view of environmental engineering the absorption test of heavy metals and leaching test regulated by Korean Waste Management Act were performed. As the results, the suitable mixing ratio of the stabilized material in the deep soil mixing barrier was determined as 13 percent. To make workability easy, the ratio of stabilized material and water was proven to be 1 : 1.5. With the results, the range of the portion of the additives(fly ash : lime= 70 : 30) was proven to be 20-40% for improving the function of the stabilized material, lowering of permeability. In heavy metal absorption assessment of the mixing barrier system with the additives, the result of heavy metal absorption was proved to be almost same with the case of the original stabilized material; high removal efficiency of heavy metals. In addition, the leaching concentration of heavy metals from the leaching test for the environmental hazard assessment showed lower than the regulated criteria.

• Journal of the Korean Geotechnical Society
• /
• v.20 no.6
• /
• pp.11-17
• /
• 2004

This study focused on the protection effects of geosynthetics installed on HDPE to resist against puncture loads. The study was conducted by a model test with various types of puncture loads created by different shapes of tools. The puncture resistance of geosynthetics installed as a protective material on HDPE is varied depending on the sizes of geosynthetics and types of puncture loads. In this study, it was found that the protection effect far all kinds of geosynthetics when a truncated cylindrical shape of puncture tool is used is lower than others. Also, geocomposite has the most excellent protection effect against all types of puncture loads.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 1997.11a
• /
• pp.35-50
• /
• 1997

쓰레기 매립장의 오수 침출 방지를 목적으로 그간 차수층이 시공되었으나 기존의 차수재는 그 성능상 많은 문제점을 내포하고 있었다. 이게 본 고에서는 '자가 형성' 및 '자가 치유'기능을 가진 SS/SH 차수층에 관하여 실내 시험 및 수도권 매립지(3공구)를 대상으로 현장 시험시공을 실시한 결과에 관해서 기술하였다. 두 시험을 통하여 SS/SH 차수층은 쓰레기 매립장 차수재로써 필요한 기준강도를 충족시키는가 하면 투수계수도 기준치를 만족시키는 낮은 수치를 나타내는 등 우수한 기능성을 충분하게 입증하였다. 무엇보다, 쓰레기 매립장에서 일반적으로 발생하는 차수층 손상에 대한 '탁월한 치유기능'을 가지고 있음으로 차수층 보수비가 전혀 필요없다는 점에서 대단히 경제적이라고 판단되었기에, 기능성과 경제성을 확보한 이 SS/SH 공법을 본공사에 적용할 수 있게 된 것이다.