배수관 내시경 조사를 통한 간접적인 관 노후도 평가방법의 적정성 연구

최태호,강신재,최재호,구자용 대한상하수도학회 2012 상하수도학회지 Vol.26 No.5

The water supply pipes are buried across wide range of areas, so it is hard to spot them using excavation and takes a large amount of expense. Thus, there is a high risk for direct research and application, accompanying many difficulties in implementation of them. Therefore, it is more economical and convenient to use indirect evaluation variables than direct evaluation of the buried pipes in assessing the degree of pipe deterioration. To assess the degree of pipe deterioration using the indirect evaluation variables, it should be done first to identify how and to what extent they affect the degree of deterioration. This study measured the evaluation variables for pipe deterioration using the pipe endoscope and analyzed the measurement results and the degree of impact on the pipes. In addition, this study attempted to evaluate the adequateness of the pipe deterioration evaluation using the indirect variables based on the analysis results. The evaluation variables measured through the pipe endoscope were the thickness of sediments, size of scale, degree of desquamation and condition of connections. For the indirect evaluation variables, the data such as the property data from GIS pipe network map as well as the material, diameter, age and pipe lining material of the pipe, road type, leakage frequency, average water velocity and water pressure using the leakage repair records was collected. Using the collected data, this study comparatively analyzed the indirect evaluation variables for the degree of pipe deterioration and the results from the pipe endoscope to choose appropriate variables for pipe deterioration evaluation and calculated the weights of the indirect variables on the degree of deterioration. The results showed that the order of the impact of indirect variables on deterioration was pipe age > pipe lining material > road type > leakage frequency > average water velocity with their weights of 0.45, 0.20, 0.15, 0.10, and 0.10, respectively. Conclusively, the results suggest that the measures of sediment thickness, scale size, degree of desquamation and condition of connections are appropriate for the evaluation of pipe deterioration and sufficient for the analysis of the impact of the indirect variables on deterioration. The water supply pipes are buried across wide range of areas, so it is hard to spot them using excavation and takes a large amount of expense. Thus, there is a high risk for direct research and application, accompanying many difficulties in implementation of them. Therefore, it is more economical and convenient to use indirect evaluation variables than direct evaluation of the buried pipes in assessing the degree of pipe deterioration. To assess the degree of pipe deterioration using the indirect evaluation variables, it should be done first to identify how and to what extent they affect the degree of deterioration. This study measured the evaluation variables for pipe deterioration using the pipe endoscope and analyzed the measurement results and the degree of impact on the pipes. In addition, this study attempted to evaluate the adequateness of the pipe deterioration evaluation using the indirect variables based on the analysis results. The evaluation variables measured through the pipe endoscope were the thickness of sediments, size of scale, degree of desquamation and condition of connections. For the indirect evaluation variables, the data such as the property data from GIS pipe network map as well as the material, diameter, age and pipe lining material of the pipe, road type, leakage frequency, average water velocity and water pressure using the leakage repair records was collected. Using the collected data, this study comparatively analyzed the indirect evaluation variables for the degree of pipe deterioration and the results from the pipe endoscope to choose appropriate variables for pipe deterioration evaluation and calculated the weights of the indirect variables on the degree of deterioration. The results showed that the order of the impact of indirect variables on deterioration was pipe age > pipe lining material > road type > leakage frequency > average water velocity with their weights of 0.45, 0.20, 0.15, 0.10, and 0.10, respectively. Conclusively, the results suggest that the measures of sediment thickness, scale size, degree of desquamation and condition of connections are appropriate for the evaluation of pipe deterioration and sufficient for the analysis of the impact of the indirect variables on deterioration.

터널 배수공의 재질에 따른 스케일 부착 특성에 관한 연구

주익찬(Chu, Ickchan),남승혁(Nam, Seunghyuk),백승인(Baek, Seungin),정혁상(Jung, Hyuksang),천병식(Chun, Byungsik) 한국지반환경공학회 2011 한국지반환경공학회논문집 Vol.12 No.11

지하수에 의하여 터널 내로 유입된 수산화칼슘(Ca(OH)<Sub>2</Sub>)이 이산화탄소(CO<Sub>2</Sub>)와 차량의 배기가스(SO<Sub>3</Sub>) 등과 반응하여 그 반응물이 터널의 배수공 내에 침전되어 배수공 클로깅 현상이 발생하였다. 대부분의 반응물은 화학분석 결과 칼사이트의 탄산칼슘 (CaCO<Sub>3</Sub>)인 것으로 나타났다. 본 연구에서는 일반적으로 터널의 배수공으로 사용되는 PVC관과 새로운 재질의 배수공인 테프론 코팅강관, 실리콘오일 코팅관, 아크릴관에 CaO 수용액과 터널 배수공 유출수를 흘려보내어 스케일 부착형태를 분석함으로써 배수공 의 재질이 스케일 부착에 미치는 영향을 연구하였다. 그 결과 PVC관에서 가장 많은 양의 스케일이 생성되었고 아크릴관, 실리콘오일 코팅관, 테프론 코팅강관의 순으로 관 표면에 스케일이 적게 부착되었다. 그러나 장기적 시험결과 테프론 코팅강관의 경우 관 표면이 터널 유출수에 포함되어 있는 토사로 인하여 손상되어 코팅재의 탈락, 강관의 부식 등이 발생하여 내구성에 문제가 있었다. The calcium hydroxide(Ca(OH)2) which is flowed into the deteriorated tunnel by groundwater is reacted with carbon dioxide(CO2) and the vehicle"s exhaust gas (SO3). So its by-products are precipitated at the drainage pipe and these cause the drainage clogging. Most by-products are composed of CaCO3 with calcite from a chemical experiment. The purpose of this study is mainly focused on comparison of attachment on each material of drainage pipe (teflon-coated steel pipe, silicon-Oil coated pipe, acrylic pipe and PVC pipe). The test was progressed to disembogue the CaO aqueous solution and tunnel outflow into each of the pipes. The experimental results show that the most produced scale pipe is PVC material and the followings are Acrylic pipe, Silicon-Oil coating pipe and Teflon coating pipe. But the long-term test results showed that teflon-coated steel pipe had a problem with durability because soil which was contained in the tunnel outflow occurred detachment of coating and corrosion of the steel pipe.

Suggestion of Deterioration Criteria According to the Condition Grade of PC Water Pipes

송승엽,이병준,최윤영 한국환경기술학회 2020 한국환경기술학회지 Vol.21 No.5

In this study, the internal and external states of domestic PC water pipes were investigated and analyzed and applicability was reviewed on the basis of the Japanese improvement judgment criteria of PC water pipes, and then the deterioration judgment criteria for domestic PC water pipes were established. The PC water pipes manufactured in Japan are similar to those in Korea. The research subjects selected were the water conveyance pipes in Pohang industrial complex and water purification facilities. These pipes were installed in 1971 to 1979 and passed over 40 years. At observatory points, resistivity of soil, chlorine ion and sulfate ion were measured. In order to analyze the relationship between pipe diameter and sound velocity value, the function of relationship between PC water pipe diameter and sound velocity value, which is used in Japan, was applied to the observed values in this study. The relational expression of Japanese PC water pipes is ‘y(sound velocity value)=0.3848×pipe diameter(mm)+3729.6’. Given the similarities of PC water pipe design method & material, field survey results, and measured values, it was not inappropriate to apply the Japanese judgment criteria for PC water pipe deterioration. Based on the cover coat thickness ‘12 mm’, concrete neutralization was tested, and then stability of the pipe body and the state of joints were investigated. After that, a PC water pipe was classified into a proper grade. The suggested judgment criteria for improvement are based on four grades. The criteria for Grade I are that a PC water pipe’s cover coat thickness is normal and has no erosion. The criteria for Grade Ⅱ are that a PC water pipe has erosion, and its cover coat thickness is more than 12 mm; that the joint separation distance is more than 18 mm, joints should be repaired partially, and the pipe should be re-diagnosed after 5 years. The criteria for Grade III are that a PC water pipe’s cover coat thickness is 10 mm-12 mm; that the pipe should be improved and enhanced structurally. The criteria for Grade IV are that a PC water pipe’s cover coat thickness is less than 10 mm; that the pipe should be replaced immediately.

Development of techniques for evaluating residual life of water pipes based on pipe deterioration evaluation results

Park, Suwan,Kim, Kimin 한국수자원학회 2017 한국수자원학회논문집 Vol.50 No.10

본 논문에서는 상수관로의 효율적인 유지 관리를 위해 상수도 기술진단에서 점수평가법으로 도출된 관망성능평가결과를 이용한 상수도 관로의 내구연수 및 잔존수명 산정 방법을 제시하였다. 본 연구에서 잔존수명은 ‘모델에 의해 추정된 매설 후 최적교체시기까지 경과년수’를 의미하는 ‘내구연수’와 매설 후 경과년수의 차이로 정의하였으며, 내구연수는 관망성능평가기준으로 제시된 노후관로 판정기준 점수에 도달하는 시점으로 정의하였다. 연구대상지역의 관망성능평가에 사용된 평가항목들과 노후도 점수를 상수도 관로의 잔존수명 추정을 위한 다중회귀모델의 변수로 사용하였다. 잔존수명의 산정에 필요한 내구연수를 추정하기 위하여 구축된 회귀모델에 독립변수로 사용된 노후도 점수를 나타내는 변수의 값으로 노후관로 판정기준 점수에 해당하는 값을 대입하였다. 개발된 회귀모델을 이용하여 연구대상지역 상수도 관로의 내구연수 및 잔존수명을 산정하였으며 그 결과를 지방공기업법에서 제시하고 있는 내용연수와 비교하여 분석하였다. In this paper a method for estimating the ‘service life’ and ‘residual life’ of a water pipe based on the Water Pipe Network Performance Evaluation(WPNPE) results of Water Supply Technical Diagnosis was developed for efficient maintenance of water pipes. The residual life of a pipe was defined as the difference between the service life and elapsed time since installation. The service life was defined as the time when a pipe reaches the reference score for determining deteriorated pipes that was used in the WPNPE. The pipe evaluation criteria and deterioration scores used in the WPNPE for the case study area were considered as independent variables in the multiple regression model for estimating the service life and residual life of the pipes in the area. To estimate the service life for the pipes the reference scores for determining deteriorated pipes were used as the values of the variables that represent the deterioration scores in the constructed regression models. Subsequently, the statistics of the service life and residual life of the pipes in the case study area were presented and analyzed in comparison with the service life defined by the Local Public Enterprizes Act.

배관 노후도 평가기준 설정

윤정기(Jung-Gi Yoon),박률(Yool Park),박종일(Jong-Il Park) 대한설비공학회 2009 대한설비공학회 학술발표대회논문집 Vol.2009 No.-

The construction for apartment building has been progressing actively to supply house smoothly since 1970s in Korea, but the renewal or remodeling for pipes with shorter life cycle than building with semi-permanent life has been implementing. In general, to diagnose a pipe deterioration has to measure a residual thickness of pipe and judge whether evaluated pipes are changed or not after assuming a residual life on the base of that, but method and standard for the evaluation of the pipe deterioration is not established correctly. Therefore, this research would establish the evaluation standard for judgement of pipe deterioration.

상수관 노후도 평가방법 개선 방안 연구

김주환 ( Ju Hwan Kim ),성권식 ( Kwon Shic Sung ) 한국수처리학회 2003 한국수처리학회지 Vol.11 No.2

The field investigation was performed to improve the evaluation process of pipe deterioration, which can be the criteria of replacements and rehabilitations of pipelines in water distribution system. To evaluate the deterioration degree of pipelines, accompanied by the field investigation, the data of pipe-related facilities and maintenance history, pipe material, soil types for installation and water qualities etc. are surveyed and collected from six sites of waterworks under local governments. All the variables which is used by conventional models were considered and selected to find out the determination stage of influential factors on the deterioration of water pipelines. The way to find those factors can be divided into two categories as direct and indirect method. Also, the check lists are proposed for the direct and indirect evaluation method for deteriorated pipes. Direct method for the evaluation of the deterioration degree of water pipeline requires excavation at laying sites to collect pre-determined factors. While. deterioration degree can be guessed or predicted roughly by indirect method using pipe history, soil condition data, and so on. Factors can be modified and corrected by the field practitioners or inspectors by consideing a field situation. Also, experts in the area of pipeline management works can judge the deterioration degree of pipeline on their old experiences and accumulated know-how.

통계적 수명곡선함수에 의한 상수관로의 노후상태 평가모델

김주환 ( Ju Hwan Kim ),배철호 ( Cheol Ho Bae ),이두진 ( Doo Jin Lee ) 한국수처리학회 2011 한국수처리학회지 Vol.19 No.5

Proper and timely maintenance of water pipes is inevitable to reduce leakage and breakage, to prevent water quality deterioration, to increase hydraulic capacity and so on. Rehabilitation of water pipes is applied to solve these problems and prolong the useful life since water pipes are most expensive part of a water supply system. Residual life of water pipes should be estimated by a current condition for the short and long-term rehabilitation planning. The remaining life of a water pipe buried underground is considerably affected from various factors such as environmental characteristics, pipe characteristics, operation and maintenance, etc. Therefore, it is difficult to determine their service life as uniformly the same value assigned by related laws and ordinances. As a result, the service life should be determined by the technical judgement based on the assessment for the condition of water pipes. In this study, the methodology is proposed to predict a residual life and plan short and long-term strategies for replacement/rehabilitation by introducing statistical life function through the current condition assessment. The methodology was applied for the verification and reliability to several sites selected in multi-regional transmission pipelines. The proposed method could helps to support reasonable and economical decision of rehabilitation/replacement in the present and future. To improve conventional assessment method of aged water pipes, affecting factors are simplified based on the statistical analysis results from the measured data in the field and the physical deterioration mechanism for better reliability.

ANN-Clustering 기법을 이용한 상수관로 노후도 평가 및 분류

이슬민,강두선 한국수자원학회 2018 한국수자원학회논문집 Vol.51 No.11

The aging water pipes induce various problems, such as water supply suspension due to breakage, insufficient water pressure, deterioration of water quality, damage by sink holes, and economic losses due to water leaks. However, it is impractical and almost impossible to repair and/or replace all deteriorated water pipes simultaneously. Hence, it is required to quantitatively evaluate the deterioration rate of individual pipes indirect way to determine the rehabilitation order of priority. In this study, ANN(Artificial Neural Network)-Clustering method is suggested as a new approach to assess and assort the water pipes. The proposed method has been applied to a water supply network of YG-county in Jeollanam-do. To assess the applicability of the model, the evaluation results were compared with the results of the Numerical Weighting Method (NWM), which is being currently utilized in practice. The assessment results are depicted in a water pipe map to intuitively grasp the degree of deterioration of the entire pipelines. The application results revealed that the proposed ANN-Clustering models can successfully assess the water pipe deterioration along with the conventional approach of NWM. 노후화된 상수관로는 단수유발, 수압부족 및 수질악화, 싱크홀 발생 피해와 누수로 인한 경제적 손실 등을 초래한다. 하지만 모든 노후관로를 일시에 보수 및 교체하는 것은 불가능하므로, 사용 중인 관로의 노후도를 정량적으로 판단하여 상수관로의 개량 우선순위를 결정해야 한다. 본 연구에서는 ANN(Artificial Neural Network)-Clustering 기법이 상수관로의 노후도 평가를 위한 새로운 평가방법이 될 수 있음을 제시하였다. 본 연구는 전라남도 YG지역의 배수관로를 적용대상으로 진행하였으며, 관망성능평가 항목을 이용하여 전체 관로를 세 개의 등급으로 분류하여 노후도를 평가하였다. 또한, 본 연구의 적용 가능성을 판단하기 위하여 실무에서 적용 중인 점수평가법 결과와 비교분석을 실시하였으며, 전체 대상관로의 노후도 정도를 직관적으로 파악할 수 있도록 산정된 노후도 등급을 관망도에 도시하였다. 본 연구에서 제안한 노후관로 평가기법은 관로의 다양한 특성값을 손쉽게 변경하여 적용할 수 있으며, 점수평가법과 더불어 상수관로의 유지관리를 위한 객관적이고 합리적인 관망성능평가법이 될 수 있을 것으로 기대한다.

Water pipe deterioration assessment using ANN-Clustering

Lee Sleemin,Kang Doosun 한국수자원학회 2018 한국수자원학회논문집 Vol.51 No.11

노후화된 상수관로는 단수유발, 수압부족 및 수질악화, 싱크홀 발생 피해와 누수로 인한 경제적 손실 등을 초래한다. 하지만 모든 노후관로를 일시에 보수 및 교체하는 것은 불가능하므로, 사용 중인 관로의 노후도를 정량적으로 판단하여 상수관로의 개량 우선순위를 결정해야 한다. 본 연구에서는 ANN(Artificial Neural Network)-Clustering 기법이 상수관로의 노후도 평가를 위한 새로운 평가방법이 될 수 있음을 제시하였다. 본 연구는 전라남도 YG지역의 배수관로를 적용대상으로 진행하였으며, 관망성능평가 항목을 이용하여 전체 관로를 세 개의 등급으로 분류하여 노후도를 평가하였다. 또한, 본 연구의 적용 가능성을 판단하기 위하여 실무에서 적용 중인 점수평가법 결과와 비교분석을 실시하였으며, 전체 대상관로의 노후도 정도를 직관적으로 파악할 수 있도록 산정된 노후도 등급을 관망도에 도시하였다. 본 연구에서 제안한 노후관로 평가기법은 관로의 다양한 특성값을 손쉽게 변경하여 적용할 수 있으며, 점수평가법과 더불어 상수관로의 유지관리를 위한 객관적이고 합리적인 관망성능평가법이 될 수 있을 것으로 기대한다. The aging water pipes induce various problems, such as water supply suspension due to breakage, insufficient water pressure, deterioration of water quality, damage by sink holes, and economic losses due to water leaks. However, it is impractical and almost impossible to repair and/or replace all deteriorated water pipes simultaneously. Hence, it is required to quantitatively evaluate the deterioration rate of individual pipes indirect way to determine the rehabilitation order of priority. In this study, ANN(Artificial Neural Network)-Clustering method is suggested as a new approach to assess and assort the water pipes. The proposed method has been applied to a water supply network of YG-county in Jeollanam-do. To assess the applicability of the model, the evaluation results were compared with the results of the Numerical Weighting Method (NWM), which is being currently utilized in practice. The assessment results are depicted in a water pipe map to intuitively grasp the degree of deterioration of the entire pipelines. The application results revealed that the proposed ANN-Clustering models can successfully assess the water pipe deterioration along with the conventional approach of NWM.

주성분 분석과 인공신경망을 이용한 인천시 상수관로의 노후도 평가

김대웅(Dae Woong Kim),장동우(Dong Woo Jang) 위기관리 이론과 실천 2021 Crisisonomy Vol.17 No.1

최근 상수관로의 노후화로 인해 많은 누수 및 수질 사고가 발생하여 경제적 손실과 더불어 사회적인문제로 대두되고 있다. 하지만 상수관로는 지하에 매설되어 많은 내·외부적인 요인에 의해 영향을받기 때문에 정확한 부식 및 노후화 정도의 예측이 어렵다. 따라서 본 연구는 최근 상수도내 노후관로 인한 피해가 발생했었던 인천시 상수관망을 대상으로 관로의 노후도 평가항목 10개를 선정하고, 노후관로와 일반관로를 대상으로 주성분 분석과 인공신경망을 이용하여 노후도를 예측하였다. 연구결과 데이터 변환을 거치지 않은 원데이터를 입력 데이터로 이용하여 인공신경망에 적용하는 것보다 주성분 분석을 통해 산출된 주요 6개 요인을 사용하여 인공신경망에 적용하는 것이 관 노후도점수평가 정확도를 높이는 것으로 나타났다. 또한, 인공신경망 시뮬레이션 최적화를 위해 은닉층내 뉴런 수를 구분하여 시행착오를 수행한 결과 은닉층 내 12개의 뉴런이 존재할 때 결정계수가가장 높게 나타났다. Recently, due to the deterioration of water-supply pipes, several leaks and water-quality accidents have occurred. Thus, this deterioration appears to be a social problem, incurring a huge economic loss. However, because the water-supply pipe is buried underground and affected by various internal and external factors, it is difficult to accurately predict the degree of corrosion and aging. In this study, 10 items were selected for evaluating the deterioration of pipelines in Incheon metropolitan city’s water supply network, which was recently damaged by old pipes. In addition, deterioration was predicted using principal component analysis and artificial neural networks (ANNs) for old pipelines. It was found that applying the six factors calculated through principal component analysis to ANNs improves the accuracy of scoring evaluation for assessment of deteriorated pipes. In addition, using a trial and error method to divide the number of neurons in the hidden layer for optimization of ANN simulation, the coefficient of determination was found to be the highest when 12 neurons in the hidden layer were utilized.