• Journal of the Korean Geotechnical Society
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• v.18 no.1
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• pp.59-70
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• 2002

Horizontal drains are sometimes installed on the ground together with vertical drains in order to drain excess pore water. Taking into account the discharge capacity of horizontal drains, a new analytical method is developed in this paper, and then a new formula for the discharge capacity of horizontal drains is proposed. It is known from the analysis that the effect of the rate of surcharge loading is negligible in determining horizontal discharge capacity. This formula is described as the function of coefficient of consolidation, space of vertical drain, compression index, length of horizontal drains, and thickness of the compressible layer.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.1
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• pp.73-78
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• 2005

It was aimed to promote Cyrtomium falcatum as a material for interior landscape by validating it indoor adaptability in the indoor environment, especially irrigation times, soil treatment and drainage level. Irrigation times were 2 times per week and 7 times per week. Soil treatment and drainage level were carried out drainage-peatmoss : vermiculite : perlite=1 : 1 : 1(D-PVP), peatmoss : vermiculite : perlite=1 : 1 : 1(PVP), drainage-saprolite : leaf mold=1 : 1(D-SL) and saprolite : leaf mold=1 : 1(SL). 1. Top of growth was better with irrigation 7 times per week than irrigation 2 times per week but indoor adaptability was decreased and shown yellowish green. 2. In case of soil treatment, growth was better with saprolite : leaf mold=1 : 1 but indoor growth adaptability was decreased than peatmoss : vermiculite : perlite=1 : 1 : 1. 3. Plant height and blade length were increased under non-drainage treatment but indoor adaptability, number of new fronds and number of sporophyll were decreased under drainage treatment, regardless of irrigation times and soil treatment. 4. Photosynthetic rate(Pn) was the highest in the drainage-peatmoss : vermiculite : perlite=1 : 1 : 1 treatment of irrigation 2 times per week and was the lowest in the saprolite : leaf mold=1 : 1 treatment of irrigation 7 times per week.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.83-96
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• 2001

선행압밀공법에서 지반으로부터 배출되는 물을 신속히 배수시키기 위해 연약지반상에 수평배수층을 설치한다. 종전의 연구에 의하면(예, Giroud(1981), 한국도로공사(1998)), 배수층의 통수능은 성토하중의 성토기간 또는 압밀속도의 영향을 받으며, 성토기간이 짧을 때에는 과다한 배수능이 요구된다. 이 논문에서는 선행압밀공법에 적용 가능한 새로운 압밀해석방법을 사용하여 소요통수능을 재검토하고 새로운 실용공식을 제안하였다. 전반적인 압밀침하량이 5%이내에서 지연될 때에는 소요통수능은 성토기간의 영향을 받지 않는다는 것을 알게 되었다. 또한 소요통수량은 압축지수, 압밀계수 및 수평배수층의 배수거리의 제곱에 비례한다는 것도 밝혀졌다.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.235-238
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• 2003

폐기물 매립시스템은 크게 폐기물의 토양으로의 유출에 의한 오염방지를 위한 lining system과 폐기물에서 발생하는 가스의 방출차단과 빗물의 매립시스템으로의 침투방지를 위한 covering system으로 나뉘어진다. Lining system은 폐기물 하부에 차수층, 침출수 배수층, 침출수 차단층과 차수재 보호층 순으로 구성되며, covering system은 폐기물 상부에 집수관을 설치한 후 중간 복토층을 둔 후, 가스 차단층, 봉합층, 배수장치와 보호층 순으로 구성되어진다. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.449-455
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• 2019

The increase in impermeable pavement from recent urbanization has resulted in an increase in surface runoff. The surface runoff has also increased the burden of the existing drainage system. This drainage system has structural limitations in that the catchment area is reduced by the waste particles transported with the surface runoff. In addition, the efficiency of the drainage system is decreased. To overcome these limitations, a new type of drainage system with a drainage layer was developed and applied. In this study, various volume porosity and permeability of the lower drainage layer were simulated using ANSYS CFX, which is a three dimensional computational fluid dynamics program. The results showed that the outlet velocity of the 35% volume porosity was faster than that of the 20% and 50% cases, and there was no relationship between the volume porosity and drainage performance. The permeability of the drainage layer can be determined from the particle size of the material, and a simulation of five conditions showed that 2 mm sand grains are most suitable for workability and usability. This study suggests appropriate values of the volume porosity and particle size of the drainage layer. This consideration can be advantageous for reducing and preventing flood damage.

• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.77-83
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• 2012

The most of horizontal drainages, which is composed of the aggregates made of sand and crushed stone, are used to improve the soft ground. However, where the aggregates are used as the horizontal drainage, it often brings about the delay of consolidation. For this reason, the horizontal drain pipe system is applied to properly improve the soft ground using a drainage pipe instead of horizontal drainage. This system is direct drain method for disappearing the excess porewater pressure which is caused by placing of fill on the soft ground. The large-scale field test was conducted in order to evaluate the applicability and constructability of the horizontal drain pipe system. The settlement characteristics of improved ground with horizontal drain pipe system was observed. It is also compared to the conventional soft ground improvement method to confirm its effectiveness.

• International Journal of Highway Engineering
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• v.9 no.2 s.32
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• pp.129-140
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• 2007

A major purpose of this study is to develop a drainage system that can quickly drain water penetrated into pavement layers to mitigate pot holes which is one of the major distress types in bridge deck pavements. This system can be established by applying a thin drainage layer between waterproof and pavement layers. The most important elements for this system are the performance of waterproof layer and construction technique for the thin drainage layer. The porous asphalt mix with the maximum aggregate size of 10mm is first developed based on the porous asphalt mix design guide proposed by NCAT, and various physical and mechanical tests are performed to confirm that the porous mix satisfies all the specification requirements. In addition, a series of laboratory tests including low-temperature bending and bonding strength tests for the MMA(Methyl Methacrylate) type of waterproofing material. It is observed from the tests that the MMA material satisfies all the specification requirements. To evaluate the Reld performance of the drainage system, a field study has been conducted on a relatively small size bridge. The QC/QA tests are conducted on the both waterproofing and pavement materials. It has been found that the drainage system works well to drain the water penetrated into the pavement layers.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.177-184
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• 2003

매립장 내의 설치된 중간 복토층(intermediate cover)은 매립 도중 혹은 매립완료 후 종종 침출수가 하부의 침출수 집배수관으로 이동하는 것을 막아 매립장 내에 일정 침출수위를 형성시킨다. 이렇듯 중간 복토층은 침출수의 원활한 순환을 막아 매립장 바닥에 형성되어야 하는 침출수위가 중간복토층 위에 형성되도록 하는데, 이는 매립장의 구조적 안정성을 깨뜨리고 주변으로 침출수 누출을 유발시키게 된다. 본 연구에서는 이처럼 중간복토층 상부에 형성된 침출수위를 저하시키기 위하여, 폐기물 매립시 중간복토층에 투수성이 뛰어나고 역학적 강도와 화학적 내구성을 갖는 배수파일(Drain Pile)을 설치할 것을 제안하였다. 배수파일은 중간복토층 상부에 형성될 수 있는 침출수를 매립장 바닥으로 배수시키고, 침출수 집배수정으로 이송이 가능하게 만든다. 또한 배수파일은 매립장 내부에 설치됨으로써 폐기물의 자체 강성을 증가시키고, 동시에 매립장의 측방유동을 막아 구조적 안정성을 확보하는 효과도 기대할 수 있다. 실내시험을 통해 배수파일 충진재로서 굴패각의 활용가능성을 확인한 결과, 산업 폐기물인 굴패각이 침출수의 pH를 중화시키고 유해물질인 NH$_{4}$$^{+}$를 제거하는데 효과적임을 확인할 수 있었다. 한편, 실제현장의 침출수흐름을 모사하기 위해 범용 프로그램(SEEP/W)을 이용하여 매립지 내에서 배수 파일의 효과를 확인하였다.

• Journal of the Korean Geotechnical Society
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• v.24 no.10
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• pp.5-15
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• 2008

The purpose of this study is to examine the validity of recycled aggregates (RAs) as a substitute for Sand-Mat material for soft ground improvement in the housing site development. To evaluate the possibility of RAs as a substitute for sand mat material, first of all, the criteria and regulations related with the quality of lateral drain layer were collected and checked. Secondly, both of the properties of RAs were compared with the properties of natural sand for the lateral drain layer. The material properties related to coefficient of permeability, pressure at-rest state and so on satisfied most standards. On the basis of the test results, RAs were used to the construction site as lateral drain layer. Accordingly, if the quality of RAs can be managed well, the application of these RAs as lateral drain layer to replace natural sand was highly effective. Also, based on cost analysis of two materials, RAs are proved to be very competitive.

• Journal of the Korean Institute of Landscape Architecture
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• v.32 no.6 s.107
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• pp.103-108
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• 2005

It was aimed to promote as a material for interior landscape by validating Rumohra aristata, in an indoor environment, especially irrigation interval, medium composition and drainage at indoor. 1. The result of physico-chemical analysis of medium composition showed that porosity, pH and Ex-Ca, Ex-Mg and Ex-K were high with peatmoss: vermiculite: perlite(1:1:1) and water contents, organic matter content, total nitrogen and cation exchange capacity were high with sand: leaf mold(1:1). 2. Growth and indoor adaptability of Rumohra aristata were better with irrigation at 2 interval per week than irrigation at 7 interval per week regardless of drainage. 3. In the case of medium composition, of growth and indoor adaptability were higher with sud: leaf mold (1:1) than peatmoss: vermiculite: perlite(1:1:1). 4. Fronds fresh weight and dry weight decreased when irrigation interval increased and were higher with sand: leaf mold(1:1) than peatmoss: vermiculite: perlite(1:1:1) treatment.