The purpose of this study is to provide the data for sewage policy by selection of demending section and priority for interceptor renovation in Daejeon Metropolitian City. The order of priority for interceptor renovation in this city is Daejean-cheon, Youdeng-cheon, Gab-cheon, Youseong-cheon and Jinjam-cheon. Length of demanding section for renovation is 5.6 km for Daejean-cheon, 11.9 km for Youdeng-cheon, 13.8 km for Gab-cheon, 10.4 km for Youseong-cheon, and 3.9 km for Jinjam-cheon, respectively. The total length for interceptor renovation is 45.6 km. Assuming 30% as partial repair and 70% total repair on trenchless replacement, total renovation cost is calculated 98.2 billion won, 3.5 billion won for Daejeon-cheon, 1.2 billion won for Jinjam-cheon, 49.7 billion won for Gab-cheon, 4.3 billion won for Youseong-cheon, and 39.5 billion won for Youdeng-cheon.

In this study, repair and reinforcement priority determining method for each component of existing dams is suggested. Condition assessment results from in-depth inspection followed by “specific guide for in-depth inspection on dams” are used. Condition assessment is subdivided into several steps and evaluation indices are determined by considering weights such as influence coefficients and adjustment factors for each component through all of the steps. These weights are counted backward to determine the priority for each component and facility. An algorithm is designed to analyze this procedure and 4 target dams are adopted to verify the method. This method can be used for establishing an efficient maintenance strategy related to the repair and reinforcement priority determination.

In this study, repair and reinforcement priority of dam facilities was estimated using dam in-depth inspection assessment score and grade. Multi-Criteria Decision Making was used for decision of priority, and assessment scores and weights of individual facilities were applied as payoff matrix and weight coefficient. The results show that different analysis results can be deducted by various MCDM method even if assessment index and weight coefficient are the same.

Domestic port facilities has increased rapidly since the late 1980s. Therefore, future maintenance demand will increase significantly. However, because of the limited budget, the maintenance budget will not increase significantly. In this study, maintenance prioritization method was proposed by Delphi study for the efficient use of the maintenance budget.