ABSTRACT
ABSTRACT: The field investigation was performed to improve the evaluation process of pipe deterioration degree, which can be used as the criteria index of pipelines’ replacement and rehabilitation 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. The field survey results cover thirty-one local sites under the inspection of 10 Korea water resources corporation (KOWACO) local water works branches. 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. 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 inspectors. Also, experts in the area of pipeline management works can judge the deterioration degree of pipeline on their old experiences and accumulated know-how. In this paper, four kinds of models are developed and compared with the previous models as on the field survey data. It shows that the developed model can predict well the deterioration degree of pipelines and good results with the improvement and consistency within tolerable acceptance limits. The proposed model can give user reasonable data to make a decision of rehabilitate/replace or not.
