• 상하수도학회지
• /
• 제34권4호
• /
• pp.251-258
• /
• 2020

Sewer deterioration models are needed to forecast the remaining life expectancy of sewer networks by assessing their conditions. In this study, the serious defect (or condition state 3) occurrence probability, at which sewer rehabilitation program should be implemented, was evaluated using four probability distribution functions such as normal, lognormal, exponential, and Weibull distribution. A sample of 252 km of CCTV-inspected sewer pipe data in city Z was collected in the first place. Then the effective data (284 sewer sections of 8.15 km) with reliable information were extracted and classified into 3 groups considering the sub-catchment area, sewer material, and sewer pipe size. Anderson-Darling test was conducted to select the most fitted probability distribution of sewer defect occurrence as Weibull distribution. The shape parameters (β) and scale parameters (η) of Weibull distribution were estimated from the data set of 3 classified groups, including standard errors, 95% confidence intervals, and log-likelihood values. The plot of probability density function and cumulative distribution function were obtained using the estimated parameter values, which could be used to indicate the quantitative level of risk on occurrence of CS3. It was estimated that sewer data group 1, group 2, and group 3 has CS3 occurrence probability exceeding 50% at 13th-year, 11th-year, and 16th-year after the installation, respectively. For every data groups, the time exceeding the CS3 occurrence probability of 90% was also predicted to be 27th- to 30th-year after the installation.

• 환경영향평가
• /
• 제10권1호
• /
• pp.73-83
• /
• 2001

Web based integrated sewer management system was developed for the analysis of sewer flow and for the optimal operation of sewer works using ArcView and SWMM. SWMM and ArcView were dynamically linked together using Avenue in order to construct user-friendly information management system. The developed system was applied to the residential area in Choonchun city to verify its utilities. All the relevant field data were analyzed on the basis of the developed system, and the modeling of sewer flow was implemented using RUNOFF, EXTRAN, TRANSPORT in SWMM. This system is now in the process of connection to the management system of stormwater, surface and subsurface environment in order to develop an integrated environmental management system. Futhermore, this system will be a critical part of overall control system of sewer works including sewer network and wastewater treatment plant. As this system can provide comprehensive prediction of flow and pollution profiles, it could serve as a tool not only for the optimal management, but also for the decision support system to examine the efficiency of planning and implementation of sewer projects.

• 상하수도학회지
• /
• 제32권5호
• /
• pp.445-451
• /
• 2018

Urban sanitary sewer systems can aid in preventing inundation, and can improve civil health by effectively disposing stormwater and wastewater. However, since sewage odor can cause adverse effects, numerous technical and administrative studies have been conducted for reducing such odor. European countries and the United States of America (USA) built modern sewer systems in the late 19th century, and have since been endeavoring to eliminate sewage odors. Several cities of the USA, such as Los Angeles (LA) that has a separate sewer system and San Francisco (SF) that has a combined sewer system, have produced and distributed odor control master plan manuals. Features common in the odor reduction plans of both these cities are that the odor reduction programs are operated in all the respective local regions and are supported by administrative systems. The primary aspectual difference between the two said programs is that the city of LA employs a sewage air purification system, whereas the city of SF controls the emission of major odor causing compounds. Compared to the existing sewer odor reduction systems of these two cities, South Korea is still in the initial phase of development. Through technical studies and policy implementations for sewer odor reduction, a foundation can be laid for improving the civil health quality.

• 한국물환경학회지
• /
• 제31권2호
• /
• pp.196-208
• /
• 2015

This study analyzed the characteristics of sewer flow and its water quality, and investigated changes in the characteristics in three areas where the sewer rehabilitation projects have been carried out. In S1 area, the patterns of the flow became regular and the range of the fluctuation decreased after the sewer rehabilitation. The flow and its BOD concentration increased. The infiltration/inflow and exfiltration showed clear distinction before and after the sewer rehabilitation in this area. In S2 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased considerably after the sewer rehabilitation. Big decrement in stormwater inflow but small in exfiltration appeared in this area. In S3 area, the patterns and the range of the fluctuation of the flow made no differences before and after the sewer rehabilitation. The flow decreased slightly and its BOD concentration increased in a small rate in this area.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2006년도 학술발표회 논문집
• /
• pp.1410-1414
• /
• 2006

Infiltration and Inflow(I/I) through the old or broken sewer are caused falling efficiency of sewage treatment plants. Recently, to solve these problems maintenance work of sewer pipes is progressing and sewer flow is metered for I/I survey. In this paper, metered sewer data at GyeongGi-Do H city for two years are analyzed by ToSS program. And this paper suggest particle use of sewer flow much data for many years.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.1012-1017
• /
• 2010

Sewer Pipes are not being managed for twenty years after laying. So, The life span of sewer pipes is on the decrease. For solve the life span decrease of sewer pipes, correct checking of questions and measure preparation are necessary through investigation in sewer pipes. This research investigated on the state of sewer pipes in the housing and industrial sites through CCTV(closed-circuit television) and device of digitalized strain investigation. And, a result is as follows. A results of PE, PVC, GRP, CSP investigations were found of pipe-transformation state by earth pressure and external load.

• 상하수도학회지
• /
• 제27권6호
• /
• pp.787-796
• /
• 2013

Sewer joint-related defect is one of the most common domestic sewer defects along with the lateral pipe problem. However, there are currently no criteria that precisely assess the joint-related sewer defects. Therefore, this study examined the joint-related sewer defects found in domestic circumstances, classified them according to the suggested defect code, and presented the examples of defect pictures. Each defect code was organized as the process of out of pipeline alignment (OPA) which shows the progress in deterioration. Each defect was classified into 5 grades depending on appropriate repair and rehabilitation method. The result of this study is expected to be useful for domestic CCTV inspectors to assess the sewer condition and helpful for managers to make a decision of repair and rehabilitation.

• 한국수자원학회논문집
• /
• 제44권10호
• /
• pp.777-786
• /
• 2011

우수관망의 최적 설계에 관한 기존의 연구 모형들은 설계강우에 대하여 관거의 연결, 관경 및 관 경사 등을 최소의 비용을 목적으로 최적화하여 왔다. 그런데 우수관망에서의 관거 내의 흐름은 관경, 관 경사와 특히 관망의 구성 형태에 따라서크게달라진다. 기존의최적우수관망설계모형들은설계유량을만족시키는것에국한되었으며, 설계기준을초과하는 강우에 따른 침수의 발생은 관망의 설계에 어떠한 고려도 되지 않았다. 본 연구에서는 우수관망을 구성함에 있어서 관거 내 흐름을 분산시키고 제어함을 목적으로 한다. 이것은 관망 구성에 따른 관거 내 흐름의 중첩효과를 제어함으로써 가능하며, 이러한 흐름의 제어를 통하여 설계기준을 초과하는 강우에 대해서 우수관망에서의 내수침수 발생은 저감될 수 있다. 본 연구에의 최적 우수관망 설계 모형(Optimal Sewer Layout Model, OSLM)은 내수침수 발생을 저감시키기 위해 흐름의 중첩효과를 고려하여 관거 내 흐름을 분산시키고 제어하기 위하여 개발되었다. 이 모형은 최적화를 위하여 유전자알고리즘(Genetic Algorithm, GA)를 이용하였으며, 수리학적 분석을 위하여 SWMM(Storm Water Management Model)을 연계하였다. 모형의 적용은 유역면적 44 ha의 서울시 하계 배수분구에 이루어졌으며, 현재의 우수관망 구성에 대하여 도출된 최적 우수관망에서는 지속기간 30분의 설계강우에 대하여 7.1%의 유출구 첨두유출량 감소와 20년 빈도의 지속기간 1시간 초과강우에 대하여 24.2%의 침수 발생량 저감 효과를 나타내었다.

• 한국방재학회 논문집
• /
• 제9권1호
• /
• pp.1-7
• /
• 2009

최적의 우수관망 설계를 위한 기존의 연구 모형들은 관경, 관 경사 등을 포함한 관거의 설계에 있어서 설계 강우에 대하여 최소의 비용을 목적으로 하여왔다. 그러나 이러한 모형들은 우수관망 관거 내 흐름의 중첩효과에 대한 고려는 하지 않고 있다. 관거 내 흐름의 특성은 관경, 관 경사 등에 따라서 달라지며 특히 관망의 구성이 달라짐에 따라서 크게 영향을 받는다. 본 연구에서는 우수관망을 구성함에 있어서 관거 내 흐름을 분산시키고 제어함을 목적으로 하고 있다. 이것은 관망 구성에 따른 관거 내 흐름의 중첩효과를 제어함으로써 가능하며, 이러한 흐름의 제어를 통하여 우수관망에서의 내수침수 위험도가 저감될 수 있다. 본 연구에서는 맨홀간 관거의 연결 방향을 조정함으로써 관내 유입량을 분산시키고 그 결과로서 유출구에서의 첨두 유출량은 저감되도록 우수관망을 구성하였다. 이때 관망 내 흐름에 대한 수리학적 분석은 SWMM(Storm Water Management Model)을 본 모형과 연계 구성함으로써 가능하였다. 관망 구성에 따른 내수침수 위험도의 저감을 검증하기 위하여 본 연구에서는 서울시 가락 배수분구의 현재 구성된 관망에 대하여 유출구에서의 첨두 유출량을 최소화하기 위하여 맨홀간 관거의 연결 방향을 변화시켰으며, 그 결과 30분 지속시간의 설계빈도 강우에 대하여 유출구 첨두 유출량은 약 20% 감소하였다. 또한 수정된 관망 구성은 설계빈도를 초과하는 강우에 대해서도 월류량 발생량이 저감되는 결과를 나타내었다.

• 산업기술연구
• /
• 제20권A호
• /
• pp.63-71
• /
• 2000

A web based watershed and sewer management system was developed for the analysis of stormwater runoff and sewer flow, and for optimal operation of sewer works using ArcView and SWMM. SWMM and ArcView were dynamically linked together using Avenue and Visual Basic in order to construct user-friendly management system. The developed system was applied to Choonchun city to verify its utilities. All the relevant field data were analyzed on the basis of developed system, and the modeling of runoff and sewer flow was implemented using RUNOFF and TRANSPORT blocks in SWMM. This system was connected to the management system of surface and subsurface environment management system in order to develop an integrated environmental management system. Futhermore, this system will be a critical part of overall control system of sewer works including sewer line and wastewater treatment plant. As this system can provide comprehensive prediction of flow and pollution profiles and analytical tool equipped with Web-GIS, it could serve widely as a tool not only for optimal management, but also for decision support system to examine the efficiency of planning and implementation of sewer projects.