• 한국지반신소재학회논문집
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• 제13권2호
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• pp.11-20
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• 2014

대단위 부지조성을 위해 해안연약지반을 매립후 공기단축 및 안정된 부지를 조성하고자 대부분 연직배수재를 이용하여 지반 개량을 시행한다. 이 과정에서 연약지반내 설치한 연직배수재를 통하여 지반내 간극수가 지표면의 수평배수층으로 이동하여 외부로 배출된다. 과거에는 이 수평배수층 재료로 모래를 사용하였으나 근래에는 재료 품귀 및 단가 상승으로 쇄석으로 조성하는데 상부 성토층과 혼재를 방지하기 위하여 토목섬유(P.P. Mat)를 설치한다. 토목섬유의 설치시 재료비 및 시공비가 발생하여 토목섬유 적용 필요성에 대하여 실내에서 모형토조를 이용하여 단계별로 하중을 달리하고 유입량을 변화시켜 실험한 결과 토목섬유 적용에 따른 통수능에는 큰 차이가 없음을 알 수 있었다.

• 한국농공학회지
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• 제9권2호
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• pp.1296-1300
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• 1967

This study was made through the utilization of heavy soil taken from the experimental plot of heavy soil in Konkuk University, Changan-dong, Sungdong-ku, Seoul. The soil used in the experiment has the following physical characteristics: 1. The soil is very compact, impervious, and unfit for any plant growth, 2. For improvement of the soil, tile drainage practice has been employed, 3. According to the general theory of tile drainage, it is unnatural that the effect of drainage is actually observed in such a soil. The followings are the results of the experiment: 1. Water moved to crosswise when the plotted soil profile was not broke. In this case the upper sloped part was dry while the bottom part was moistned. The upper part of the tile was also moistned. 2. The crosswise movement of water was not observed in the artificially broken plot of subsoil. However, the water flow from the tile was observed for long period as a result of the increase of soil void, seepage, aeration, and water holding capacity. However, the water flow from the tile in the plot of unbroken subsoil was observed only in short period and soon the flow was stopped. 3. the distance between the tile laid in the heavy soil should not exceed 10m for the efficient drainage. 4. When the pF is 2.5 in the subsoil the moisture content was between 23.97% and 28.20%. However, when the water saturated in the subsoil the moisture content was between 34.30% and 22.10%. Accordingly without the higher pF than 2.5 the water can not be absorbed and therefore the drainage can not be occured.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.223-230
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• 2000

Sand drain as a vertical drainage is widely used in soft ground improvement. Recently, sand, the principal source of sand drain, is running out. The in-situ tests were carried out to utilize gravel as a substitute for sand. In-situ tests area was divided into two areas by material used. One is Sand Drain(SD) and Sand Compaction Pile(SCP) area, the other is Gravel Drain(GD) and Gravel Compaction Pile(GCP) area. Both areas were monitored to obtain the information on settlement, pore water pressure and bearing capacity by measuring instruments for stage loading caused by embankment. The results of measurements were analyzed, The clogging effect was checked at various depth in gravel column after the test. According to the test results, the settlement was found to be smaller in gravel drain than in sand drain. The increase in bearing capacity by gravel pile explains the result. The clogging effect was not found in gravel column. It is assumed that gravel is relatively acceptable as a drainage material. Gravel is considered to be a better material than sand for bearing capacity, and it is found that bearing capacity is larger when gravel is used as a gravel compaction pile than as a gravel drain.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회
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• pp.969-978
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• 2010

In this study, a laboratory model test on utilization of recycled aggregates and crushed stone as vertical drains to use alternative material of sand in soft ground is performed. The vertical and horizontal coefficient of permeability of the recycled aggregates and crushed stone showed largely 1.2~4.0 times and 3.0~3.3 times greater than sand, respectively. Therefore, it showed enough to be an alternative material to the sand which had been being used as the vertical and horizontal drainage material before. The variations of pore water pressure with time showed constantly regardless of the load in all vertical drainage materials. When water level drops suddenly, the pore water pressure of the recycled aggregate and crushed aggregate is reduced to nearly zero. Therefore, it was applicable to the field because discharge capacity was similarity to that of sand. The settlement in crushed aggregates and recycled aggregate decreases gradually with the load increase. When water level drops suddenly, earth pressure in all drains materials was evaluated the equivalent drainage capacity similarity to sand because it show approaching the nearly zero.

• 농업과학연구
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• 제37권1호
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• pp.97-104
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• 2010

In this study, a laboratory model test on utilization of recycled aggregates and crushed stone as vertical drains to use alternative material of sand in soft ground is performed. The vertical and horizontal coefficient of permeability of the recycled aggregates and crushed stone showed largely 1.2~4.0 times and 3.0~3.3 times greater than sand, respectively. Therefore, it showed enough to be an alternative material to the sand which had been being used as the vertical and horizontal drainage material before. The variations of pore water pressure with time showed constantly regardless of the load in all vertical drainage materials. When water level drops suddenly, the pore water pressure of the recycled aggregate and crushed aggregate is reduced to nearly zero. Therefore, it was applicable to the field because discharge capacity was similarity to that of sand. The settlement in crushed aggregates and recycled aggregate decreases gradually with the load increase. When water level drops suddenly, earth pressure in all drains materials was evaluated the equivalent drainage capacity similarity to sand because it show approaching the nearly zero.

• 한국지반공학회논문집
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• 제25권9호
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• pp.67-76
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• 2009

연약지반은 해성점토, 실트질, 사질토 등과 같은 지반으로 항만, 공항, 교량과 같은 구조물의 축조시 지지력 부족 및 침하, 전단변형 등의 문제점을 가진다. 이러한 문제점을 개선하고 연약지반의 조기 침하 및 강도증진을 위해 다양한 지반개량공법들이 적용되고 있으며 연약지반의 압밀에 소요되는 시간을 단축시키기 위해 연직배수공법이 많이 사용되고 있다. 본 연구에서는 대심도 연약지반에 적용될 PBD(Plastic Board Drain)공법에 대해 적용성을 분석하기 위해 SD(Sand Drain)와 비교하여 복합통수능실험을 실시하였다. 실험결과, 배수재의 최소통수능은 단일코아PBD의 경우 $400kN/m^2$이상에서 $10cm^3/sec$이상으로 측정되고 $500kN/m^2$이상에서 $5cm^3/sec$이하로 측정되며, 이중코아PBD의 경우 $500kN/m^2$이상에서 $10cm^3/sec$이상으로 측정되었다. 한편 $500kN/m^2$이상에서 SD의 최소통수능은 $0.4cm^3/sec$까지 떨어지는 것으로 나타났다. 따라서 이중코아 PBD를 사용하는 것이 대심도 연약지반개량을 위해 효과적임을 알 수 있었다.

• 한국지반환경공학회 논문집
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• 제12권12호
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• pp.37-46
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• 2011

연직배수공법은 효과적인 연약지반 압밀촉진 방법으로 적용빈도가 증가하고 있다. 연직배수 공법 중에서 PBD공법은 현재 가장 많이 사용되고 있는 압밀촉진공법으로 경제성 및 시공성 면에서 우수하나, 환경오염 및 대심도의 경우 배수재의 굴곡으로 인한 통수능 저하 문제점을 지니고 있다. SCP공법은 과거에 통수능력이 우수하여 많이 사용되었으나, 재료의 수급불균형으로 인한 가격급등으로 현재는 과거보다 사용이 많이 줄고 있는 실정이다. 이에 따른 대책 재료로 쇄석말뚝을 이용한 GCP공법이 대두되고 있다. 따라서 GCP공법의 통수능 효과를 분석하기 위하여 ${\phi}38{\times}70cm$의 원형토조를 이용하여 쇄석말뚝과 비교대상인 모래말뚝, PBD공법의 3종류의 연직배수재를 이용하여 복합통수능 실험을 실시하였다. 또한, 쇄석말뚝의 클로깅(Clogging) 범위를 파악하기 위하여 $1.0m{\times}0.5m{\times}1.1m$ 대형토조를 정면에 투명 아크릴로 제작하여 하중단계별 클로깅(Clogging) 범위를 분석하였다. 복합통수능 시험결과 하중증가에 따른 간극비 감소 및 클로깅(Clogging) 현상이 많이 발생한 GCP공법에서 가장 적게 발생하였으며, 또한 GCP 공법의 클로깅(Clogging)의 범위는 거의 10% 내에서 발생하는 것으로 분석되었다.

• 핵의학기술
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• 제22권1호
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• pp.28-34
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• 2018

국내 의료기관의 방사성옥소(I-131) 사용과 관련하여 배수 중 방사능농도가 원자력안전법의 허용치를 초과한 사례가 발견되어, 원인 분석 및 배수 중 방사능농도 분석을 통해 주변 환경 공공수역에 대한 관계를 평가하여 유용성에 대해 알아보고자 한다. 2014년 11월 1일부터 2015년 4월 30일까지 6개월에 걸쳐 국내 20개 병원을 대상으로 하였다. 장비는 HpGe 감마선 분광 측정기(Canberra DSA1000)를 사용하였으며, 분석방법으로는 GENIE-2000 Analysis을 이용하여 방사성옥소의 배수 중 방사능농도를 측정하여 비교 분석하였다. 연구 결과, 7개 기관이 I-131 배수 중 배출관리 기준을 초과하였음을 확인하였으며, 20개 병원의 평균 배수 중 방사능 농도는 $4.21E+4 Bq/m^3$로 나타났다. 방사능농도가 높은 병원의 특징으로는 I-131을 이용한 다수의 외래환자 진료 건수, 외래전용 화장실의 부재로 확인되었다. I-131 whole body scan 전 반드시 소변을 보게 하는 과정에서 체내에 잔류한 I-131이 배출되는 것으로 판단된다. 공공수역 내 배수 중 방사능 농도가 초과 검출되는 원인으로는 진료용 방사성옥소라 판단되며, 저용량 투여환자 외래전용 화장실 설치와 안전관리 지침서 제공 및 교육 강화의 중요성을 확인할 수 있었다. 또한 배수 중 배출관리기준과 관련하여 법적, 제도적 관리 체계 구축이 필요할 것으로 사료된다.

• 한국기계가공학회지
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• 제16권2호
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• pp.34-43
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• 2017

Large amounts of household water are required as common households change from the single-residence types of the past to group-residence types. Therefore, the management of reservoirs is urgently required to ensure the supply of clean household water to users. Important considerations for household water include the duration for which the water is stored in the reservoir, the disinfectant's dilution capacity, and the size of the reservoir to allow for the amount of water required for emergencies and firefighting. The drainage efficiency was analyzed in this study using computational fluid analysis for existing rectangular reservoirs and the newly proposed hexagonal reservoir. Thus, it was determined that the centrifugal force generated at the inlet was maintained until the outlet due to the approximately circular shape of the hexagonal reservoir. The findings of this study verified that the centrifugal force improved the flow rate by approximately 35% compared to existing rectangular reservoirs and that drainage was performed efficiently without stagnation zone.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.194-202
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• 2009

The paper deals with the countermeasure against structure-borne noise source and noise reduction of drainage pipes. Recently, the problem the problem of the toilet drain noise of an apartment house has been become the center of public interest and a target of public grievance. Generally, the drain noise of a toilet in the apartment house has a pink noise characteristics below 2 kHz level, and therefore, the structure-borne noise has a great effect on the entire drain noise. In order to measure the transmission loss for various kinds of pipes such as PVC pipes, cast-iron pipes and newly developed AS pipes, experimental setup containing speakers as a sound source was designed and manufactured. The second-stories measurement room with a small size anechoic chamber was constructed and the noise level for different kinds of drainage pipes was measured by the sound level meter. Through the experimental research in the study, noise reduction capacity for various kinds of drainage pipes and countermeasures against structure-borne noise source are demonstrated.