• 한국물환경학회지
• /
• 제21권1호
• /
• pp.52-58
• /
• 2005

The assessment on characteristics of hydraulic behavior and water quality variations of underground reservoirs of buildings were studied. Firstly, it was thought that underground reservoir capacities($m^3$) of buildings should be not determinated by the uniform and same methods but be estimated on the basis of the dwelling areas on dominated households and their residential characteristics, because these characteristics influence significantly on actual water usages and patterns of buildings. Secondly, it was likely that the average reduction rate of residual chlorine in underground reservoirs were affected from the their capacities, because the average reduction rate of residual chlorine in underground reservoirs under $1,000m^3$ was 43 percent, on the other hand, that rate of underground reservoirs over $1,000m^3$ was 60 percent. Thirdly, through the field investigation, the retention time of drinking water in underground reservoirs were in the range from 0.3 day to 3.9 day. In addition to, the average reduction rate of residual chlorine were depended largely on the retention time of drinking water. When the retention time was under 24 hours, the average reduction rate of residual chlorine was 45 percent, and in case of over 24 hours, was 49 percent. Fourth, water level in underground reservoirs was averagely varied in the range from 0.1 m to 2.65 m at the height of underground reservoirs. If considered actual height of underground reservoirs, 37.6 percent of the height of underground reservoirs was only used. Consequently, the frequency of the inflow and outflow of drinking water in underground reservoir were very increased, and had an effect on the reduction of residual chlorine. Lastly, the investigations on hydraulic structure characteristics of underground reservoirs inside showed the locations of inflow and outflow of drinking water almost were in the opposite direction. And some buildings had several baffles in the middle. Nevertheless, their installations had no beneficial for the improvement of water quality.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
• /
• pp.690-694
• /
• 2003

Groundwater preferentially flows through sediment layers with high permeability such as colluvium. Its flow paths are called groundwater vein streams. An underground temperature survey is a method to locate vein streams by underground temperature anomalies associated with flowing groundwater. A groundwater flow system near an irrigation reservoir located in the upper part of a landslide block was surveyed with this method. After a geomembrane lining was installed in the reservoir, the total cross-sectional area of the vein streams in the aquifer decreased to as little as 0.35 times that before installation of the liner. A change in groundwater quality also indicated that the mixing of groundwater with leaked water from the reservoir stopped after installation of the lining.

• 한국물환경학회지
• /
• 제39권2호
• /
• pp.153-161
• /
• 2023

The reservoir tank in an apartment is crucial for maintaining the quality of drinking water after it has undergone treatment. Investigating the water quality and potential contaminants in the reservoir tank is essential to ensure the safety of the drinking water. This study examined the water quality and precipitated suspended solids that accumulate at the bottom of the reservoir tanks in four apartments located in Gyeonggi province. As a result of the water quality investigation, turbidity increased proportionally to the distance from the water treatment plant (WTP) to the household. Heavy metals were also detected in the reservoir tank inlet but not in the water supplied from the WTP. The precipitated suspended solids (SS) in the reservoir tank contain high levels of heavy metals and total organic carbon (TOC). The precipitated SS mainly consists of Al, Mn, and Fe, which are expected to be a combination with turbidity-inducing substances. The X-ray diffraction (XRD) analysis revealed the presence of γ-FeO(OH), MnO₂, and β-Fe₂O₃ in the SS. Additionally, F-EEM analysis indicates that the dissolved organic matter in the SS is mainly derived from a natural water source and microorganism activities, including metal-oxidizing bacteria and biofilms that can absorb metal ions. Based on these findings, several countermeasures can be taken to prevent the inflow of SS into the household, including regularly cleaning the reservoir tank, replacing or cleaning old pipes in the water supply system, and implementing monitoring and filtering systems to manage the SS.

• 한국물환경학회지
• /
• 제20권4호
• /
• pp.313-320
• /
• 2004

In this study, variable characteristics of drinking water and the influences on underground water reservoirs, rooftop water tanks, and service water pipes in the building were assessed. The influence of underground water reservoir material and water capacity on water quality also were assessed. The results are the following as; First of all, the drinking water passing through underground water reservoirs or service water pipes in the building, averagely metal component concentration more increased from percent of 41.3 to percent of 74.2 totally than other items of water quality. On the other hand, both residual chlorine and total solid highly decreased 65.6 percent and 35.3 percent, respectively. Therefore, it was thought that water quality could be getting worse for microorganism re-growth by residual chlorine reduction, and total solid also could be a cause for extraneous matters accumulated in water reservoir. Secondly, the variations on water quality of each stage for water supply system in the building were higher in water service pipes connected from rooftop water tanks to the tap than in underground water reservoirs. In addition to, among of twelve items on water quality, ten items on water quality except dissolved oxygen and residual chlorine increased. Therefore, it was thought that the influence of water service pipes connected from rooftop water tanks to the tap on water quality were higher than other stages of water supply system in the building. Thirdly, in case of materials of underground water reservoir, it was likely that the variation on water quality by stainless steel and concrete materials got some similar. In case of water capacity, the variations on water quality of underground water reservoirs over $1,000m^3$ higher than those under $1,000m^3$. That reasons was likely that the retention time(49.72 hours averagely) of underground water reservoirs over $1,000m^3$ was two times longer than it of those under $1,000m^3$(23.37 hours). Therefore, it was thought that the influence on water quality by materials were some similar, but in case of water capacity, the influence of underground water reservoirs were higher.

• 한국물환경학회지
• /
• 제38권6호
• /
• pp.275-281
• /
• 2022

To maintain water quality after water treatment, monitoring whether the quality of treated tap water quality changes is essential. However, current investigations are insufficient to prevent secondary contamination in drinking water supply systems. This study investigated Gyeonggi's e apartment where a red water problem occurred and monitored the water quality and corrosiveness of the overall water supply system to the apartment from June 2021 to April 2022. In a comparison of drinking water quality after water treatment and the influent of the reservoir, turbidity and heavy metal concentrations were increased and residual chlorine was decreased due to increases in temperature. Correlation analysis and principal component analysis (PCA) indicated that a low level of residual chlorine may cause the abscission of Mn²⁺ and Fe²⁺ through microorganism activation, which also causes a high level of turbidity. The corrosion index (LI) in the influent of the reservoir tank was increased due to Ca²⁺ and temperature. These results indicate that the corrosiveness of drinking water and the deterioration of drinking water quality were mainly increased between the drinking water treatment plant and the reservoir tank's influent. The findings provide clear evidence that it is essential to manage water supply systems and reservoir tanks to prevent the secondary contamination of drinking water.

• Geomechanics and Engineering
• /
• 제17권2호
• /
• pp.215-225
• /
• 2019

The mechanical behavior of rock is essential to estimate the capacity and long-term stability of $CO_2$ storage in deep saline aquifers. As the depth of reservoir increases, the pressure and temperature that applied on the rock increase. To answer the question of how the confining pressure and temperature influence the mechanical behavior of reservoir rock, triaxial compression experiments were carried out on brine-saturated sandstone at elevated temperature. The triaxial compressive strength of brine-saturated sandstone was observed to decrease with increasing testing temperature, and the temperature weakening effect in strength enhanced with the increase of confining pressure. Sandstone specimens showed single fracture failures under triaxial compression. Three typical regions around the main fracture were identified: fracture band, damaged zone and undamaged zone. A function was proposed to describe the evolution of acoustic emission count under loading. Finally, the mechanism of elevated temperature causing the reduction of strength of brine-saturated sandstone was discussed.

• 한국습지학회지
• /
• 제23권1호
• /
• pp.1-6
• /
• 2021

부산지역의 연평균 강우량은 지속적으로 증가하고 있으며 부산광역시 소재 온천천의 경우는 자주 상습침수가 발생하였다. 온천천의 지형적 특징으로 중·하류부는 비교적 평탄하며 도심지가 발달하였다. 따라서 이상호우 시 하천 범람이 잦고 침수피해가 크기 때문에 이상호우 시 온천천의 유량을 효과적으로 배제할 방법이 필요하다. 본 연구에서는 온천천의 홍수저감 대책으로 동쪽에 위치한 회동저수지로 지하수로를 구축하였으며 EPA-SWMM으로 모의 분석하였다. 유역구성 시 필요한 정보들은 GIS를 활용하였다. 수영강 중류부에 회동저수지가 있으며 댐이 설치되어있다. 지하수로를 구축하여 온천천의 침수저감률을 분석하였으며 지하수로를 통한 온천천의 유량이 회동저수지로 넘어갔을 시 수영강에 미치는 영향도 분석하였다. 본 연구에서 설정한 침수위험지점에 대한 침수저감률은 지하수로를 설치하였을 때 평균적으로 24.64%가 저감되는 것으로 분석 되었으며 수영강으로 유량 배제 시 수영강에는 평균적으로 1% 유입량이 늘어났기 때문에 밀집한 도심지의 경우에 시민의 생명과 재산을 상당히 보호할 수 있을 것으로 판단되고 본 연구에서 제안하는 지하수로의 효용성이 있다고 사료된다.

• 터널과지하공간
• /
• 제28권4호
• /
• pp.304-324
• /
• 2018

싱가포르는 국토가 부족한 도시 국가의 특성으로 인해 지하 공간의 개발 및 활용을 정부차원에서 전 국가적으로 강력하게 추진하고 있다. 특히 지하철과 지하 도로와 같은 일반 얕은 심도의 지하공간의 활용뿐 아니라 대규모 지하공간 사업으로서 암반 내 지하 탄약 저장고 프로젝트를 성공적으로 마친 이후, 두번째 대규모 암반 지하공간 프로젝트인 Jurong Rock Cavern을 얼마전 준공한 바 있다. 본 논문에서는 싱가포르의 지질 분석을 통해 암반 지하공간 개발의 조건에 대해 평가한 후, 싱가포르의 다양한 지하공간 개발의 역사와 현황을 살펴본다. 지하 저수지, 지하 자동화 물류 시스템 및 물류 저장 창고 등 정부 차원에서 향후 추진이 예상되는 창의적인 암반내 주요 지하공간 관련 계획 및 기술적인 이슈들에 대해서 소개한다. 또한 이러한 대규모 암반 지하공간 개발에 관련된 향후 문제와 이슈들에 대해서 논의한다. 싱가포르의 이러한 적극적인 지하공간 개발 움직임은 또한 암반공학 및 업계에 향후 많은 기회와 과제를 줄 것으로 기대된다.

• 한국지반환경공학회 논문집
• /
• 제21권9호
• /
• pp.5-14
• /
• 2020

본 연구에서는 시멘트와 유사한 경화반응을 나타내어 붕괴된 비탈면의 복구공사에 사용되고 있는 표층안정재를 노후된 저수지의 보강재료로 활용하기 위해 실내시험과 모형시험, 프로그램 해석을 실시하여 보강효과를 분석하였다. 실내시험을 통해 혼합비에 따른 점착력과 내부마찰각의 변화를 분석한 결과, 표층안정재의 혼합비는 9%가 적절한 것으로 나타났다. 실내시험 결과를 토대로 혼합비 9%를 적용하여 모형시험과 프로그램 해석을 실시한 결과, 표층안정재를 사용한 경우에는 제내지 비탈면의 일부와 제체 아래에서만 물의 흐름이 발생하여 제체 내부에서 물의 흐름을 감소시킬 수 있으며, 침투유량은 약 42%, 제체 내부에서의 포화면적은 약 73% 감소시킬 수 있어 노후된 저수지의 안정성을 확보할 수 있는 것으로 분석되었다.

• 한국가스학회지
• /
• 제17권2호
• /
• pp.9-20
• /
• 2013

고갈가스전은 저류층을 개발할 당시 충분한 탄성파 탐사 및 시추 등을 수행하기 때문에 지질구조와 저류층의 물성 등의 파악이 완료된 상태이므로 가스저장전으로의 전환이 용이하다. 이러한 고갈가스전을 가스저장전으로 전환 시 저류층의 압력을 유지하기 위한 쿠션가스는 재생산을 위해 주입된 워킹가스의 재생산율에 영향을 미친다. 본 연구에서는 쿠션가스와 가스재생산율과의 관계 및 재생산 사이클에 따른 적정 쿠션가스의 양을 분석하기 위해 가스저장전의 주입 및 재생산에 대한 시뮬레이션을 수행하였다. 주입 및 재생산 사이클은 5개월 주입 5개월 생산, 7개월 주입 3개월 생산 두 가지 경우에 대한 분석을 수행하였다. 본 시스템을 대상으로 수행한 분석결과, 5개월 주입 5개월 생산 사이클의 경우 최소 10개의 생산정으로 50%의 쿠션가스를 유지해야 안정적인 생산이 가능하였고, 7개월 주입 3개월 생산 사이클의 경우 12개의 생산정으로 60%의 쿠션가스를 유지해야 안정적인 재생산이 가능한 것으로 산출되었다.