马里兰州巴尔的摩县实施了最先进的评估和评估 其中一条PCCP输水干管的管理计划。这个 传输干线是从主要泵站到大型泵站的48英寸供水馈线 成品水库。他们评估项目的一个主要重点是利用 非破坏性技术，用于评估主管道并识别积极腐蚀的PCCP。 该项目由两个阶段组成:电磁测试与测试同时进行 第一阶段的目视检查；第二阶段的声学监测。第二阶段 随后，根据第一阶段的结果对该计划进行了修订 检查和不断发展的技术的同时可用性。 第一阶段的结果表明，大约16%的管段包括 被检查的1.5英里长的管道出现了电线断裂。共有四个管段 确定需要立即更换主管道，然后才能将其恢复使用 服务更换管道后，将四个管段作为一部分进行解剖 法医分析。将实际断丝数与实际断丝数进行比较 之前预测使用电磁检测技术。 在第一阶段检查之后，该县的第二阶段评估计划被取消 修改后采用新技术，使用“光纤”代替计划中的 “声学”技术。光纤技术正被用于监测正在进行的测试 90天内电线断裂。此外，出于试验目的 技术也在被并排比较，以获得正在开发的一小段管道 监控。 本文以巴尔的摩县主干道为例讨论了腐蚀问题 PCCP的机制，以审查可供用户使用的最新技术和方法 评估PCCP main，并对其在中国的就业结果进行评论 管道评估和管理计划。 包括参考资料、表格、图表。

Baltimore County, Maryland has implemented a state-of-the-art assessment and management program for one of their PCCP water transmission mains. The transmission main is 48-inch supply feeder from a major pumping station to a large finished water reservoir. A major focus of their assessment program has been to utilize non-destructive techniques to assess the main and identify actively corroding PCCP. The program consisted of two phases: electromagnetic testing simultaneously with visual inspections for Phase 1; and, acoustic monitoring for Phase 2. The Phase 2 program was subsequently revised based upon the results from the initial Phase 1 inspection and the simultaneous availability of evolving technologies. Phase 1 results showed that approximately 16 percent of the pipe sections comprising the 1.5 mile pipeline inspected exhibited wire breaks. Four pipe sections were identified as requiring immediate replacement before the main could be returned to service. Subsequent to pipe replacement, the four pipe sections were dissected as a part of forensic analysis. The actual number of wires broken were compared with those previously predicted using the electromagnetic inspection techniques. Following the Phase 1 inspection, the County's Phase 2 assessment program was modified to incorporate new technology which uses "fiber optics" in lieu of the planned "acoustic" technology. The fiber optic technology is being used to monitor on-going wire breakage over a 90-day period. In addition, and for trial purposes, both technologies are also being compared side by side for a short section of the pipe being monitored. The paper uses the case study of the Baltimore County main to discuss corrosion mechanisms of PCCP, to review the latest technologies and methodologies available to assess the PCCP main, and to critique the results stemming from their employment in the pipeline assessment and management program. Includes reference, tables, figures.