An Optimal Inspection/Rehabilitation Model for Sewage Work Facilities

• Published in: INFRASTRUCTURE PLANNING REVIEW Vol. 25; pp. 213 - 224
• Main Authors: KOBAYASHI, Kiyoshi, KAITO, Kiyoyuki, HORI, Michihiro, OBAMA, Kengo
• Format: Journal Article
• Language: English
• Published: Japan Society of Civil Engineers 30.09.2008
• ISSN: 0913-4034; 1884-8303
• DOI: 10.2208/journalip.25.213

For the asset management of sewage facilities, water needs to be discharged from the disposal tank to carry out inspection or repair. Therefore, to inspect or repair the system, it is necessary to suspend the operation of the sewage disposal tank temporarily, and so the inspection or repair work should be finished swiftly. Accordingly, if some damage is detected during inspection, it is repaired immediately. In addition, it is not easy to obtain the information on the deterioration state of the concrete plates of the disposal tank, and so in many cases, available information is limited to that on the repair amount for damage type (the information on damage area). This study constructs a model while assuming that the deterioration process of sewage facilities with the above mentioned characteristics follows the aggregative Markov process, and proposes the optimum inspection/repair model for estimating the inspection/repair cycle that minimizes the expected lifecycle cost. The paper concludes by illustrating the importance of preventive policies based upon a case study dealing with the actual sewage disposal facilities.