由于垦荒局（填海）和业界的关注，填海工程已与AWWA研究基金会进行了两年的合作研究，以解决与预应力混凝土管相关的问题。由于保护投资是头等大事，因此最初主要致力于确定可靠评估管道运行状况的诊断技术，以及探索经济修复或修复受损管道的方法，同时尽量减少服务中断。目前的设计方法中使用的假设以及更好地保护管道免受潜在破坏性环境影响的工程规定的有效性也在分析中。本文论述了整个项目的一个关键阶段，即修复和修复阶段，以及该阶段的一个主题，即对亚利桑那州中部项目虹吸管进行的新的和独特的修复的研究、开发、实施和监测。 虽然这些维修是在大直径管道上进行的，但也适用于小尺寸管道。

Because of the Bureau of Reclamation (Reclamation) and industry concerns, Reclamation has undertaken a 2-year collaborative study with the AWWA Research Foundation to address problems associated with prestressed concrete pipe. Since protecting the investment is a top priority, efforts are initially and primarily being directed towards identifying diagnostic techniques which reliably assess the condition of pipe inservice as well as exploring ways to economically repair or rehabilitate distressed pipe with minimal service disruption. Assumptions used in current design methodologies as well as the effectiveness of the engineering provisions which better protect the pipe from potentially destructive environments are also being analyzed. This paper addresses one critical phase of the overall program, the repair and rehabilitation phase, and one topic from the phase, namely the research, development, implementation, and monitoring of the new and unique repairs that were performed on the Central Arizona Project siphons. Although these repairs were performed on large diameter pipe, they would be applicable to small sizes as well.