未使用既有污水下水道幹管狀況調查與修繕-以臺東市幹管為例

臺東市污水下水道系統自民國89年至93年間建置管徑300mm至1,200mm鋼筋混凝土管(RCP)，長度約4,667m之幹管，因當年BOT招商未果，致建置完成之污水幹管遲未啟用，經修正計畫後，機關將啟用竣工近20年之幹管，為確認既有幹管狀況，採CCTV調查管線設施，發現破孔、接頭漏水、嚴重積水及障礙物等4類缺失，經考量功能、施工條件、施工成本後，以局部修補、局部翻修、新推管線及機械臂障礙切除等工法修繕，延長幹管使用壽命，該污水系統並於民國109年通水啟用。本研究蒐集常見污水下水道修繕工法、人孔及管線巡視調查方法，並以臺東市未經使用之污水下水道幹管為例，進行探討啟用前狀況調查與修繕分析，得以下主要結論供參考：(一)以經濟效益評估，免開挖工法應用於污水幹管修繕較開挖工法為佳。(二)於交通繁忙、污水通水區域，修繕時無法繞流或止水困難時，免開挖螺旋內襯工法在施工快速、少量水中施工及減少養護時間等優點較現場固化內襯管(CIPP)為佳。(三)管線維護管理比建設更為重要。(四)建置完整污水設施數位資料十分重要。(五)CCTV的多功能技術運用可避免人員進入管線可能的風險，對下水道產業來說，是相當重要的一環。

關鍵字

污水下水道；管線調查；管線修繕

並列摘要

The Taitung City sewer mainlines were part of the City sewer system and were constructed from 2000 to 2004. These mainlines consisted of 300 mm to 1,200 mm diameter Reinforced Concrete Pipes (RCPs) with a total length of about 4,667 meters. Originally, the sewer system was design as a BOT project. Since this BOT sewer system was unable to contract out, therefore these sewer mainlines were unable put in service since the completion. After a re-planning sewage project was approved by the Taitung City government, a CCTV pipeline investigation program was conducted to assess the condition of these sewer mainlines in order to put these pipelines in service after nearly 20 years completion of this system. The assessment program found out 4 major service issues of these pipelines. These issues included one flooded pipe section due to unknown reasons, one broken pipe section, several joint leakages, and some obstacles. In considering of the function of service, the construction cost, and the construction availabilities, the flooded pipe section was replaced using a new constructed 800 mm RCP jacked pipe section, the spiral lining local repair technique was used to repair the broken pipe section, localized repair technique was conducted to stop the joint leakages, and a robot removal system was used to clear the obstacles. The sewage system was put in service in 2020 after the rehabilitation project was completed. This study had reviewed those common repair and assessment techniques for sewer and manholes related to this Taitung City sewage pipeline rehabilitation project. After complete this study, the following conclusions are made. First of all, in considering of construction destruction of local business and social economic benefits reasons, trenchless technology is a better solution for this rehabilitation project in the center city of Taitung in comparing with the open cut method Secondly, due to the broken pipe section needs to maintain water flow condition during repair construction, spiral lining local repair method is a better solution in comparing with Cured-in-Place Pipe (CIPP) method which requires larger working zone in busy traffic street for construction. Thirdly, even construction of new sewage system for civilian is important tasks, providing long lasting management and maintenance program for these sewage system is more important to provide a better life for people of Taitung city. Fourthly, it is also important to establish a detail digital data of sewage facilities for future maintenance needs. At the end, the application of CCTV can avoid the risks of service person entering the existing sewage pipelines which is a very important needs for the sewer industry.