Condition-Based Asset Management: Investigation, Assessment Of The Oakland Macomb Interceptor System

U-TECH
By John R. Kosnak, P.E., M. SAME and Harry R. Price, P.E., F. SAME | October 2012, Vol. 67 No. 10

As the initial phase of the restoration was concluding, the Edison Corridor was re-inspected using a combination of CCTV, laser measurement and sonar. The need for the re-inspection and proposed schedule for this work was identified in the 2008 reports. In addition, suspect areas identified by the MASW testing were investigated with a series of test borings. The CCTV data was again recorded using PACP and compared to the reports from the initial inspections. The data from the current inspection indicated that the deterioration had advanced from the 2007/2008 condition investigations. Areas where the coarse aggregate was exposed in the previous studies had lost additional cement paste due to microbial induced corrosion (MIC) such that the coarse aggregate was now projecting. In areas where the coarse aggregate was projecting in the previous condition survey now exhibited aggregate lost. When comparing the reports for the 2007/2008 reports to the present investigation, it was also clear that the distressed areas had expanded in size. Due to the increase in distressed areas, an adjustment to future repair program component was warranted

Without the use of the standardization of PACP, a direct comparison of the CCTV data between inspections would have been difficult. With the ability to directly compare the data, it allows for a data based adjustment to the proposed restoration program. Further, the comparison allows the project owner to understand the necessity for the program adjustments. The laser, sonar and other supplemental testing in conjunction with the CCTV data, facilitates the development of restoration drawings.

In summary, the NASSCO’s Pipeline Assessment and Certification Program is a useful tool in condition based asset management. The use of PACP’s standardized descriptions allows the rate of change in distress to be monitored. Further, NASSCO has also undertaken the approval of the software used to record the condition survey data; thereby assuring that regardless of who provides the program used to record the data, if it is NASSCO approved it can be read and imported into another manufacturer's approved software program. This ability to transfer data between programs is critical when the CCTV records are prepared by different providers, each of which may be using different data management software to record their data.

ABOUT THE AUTHORS:
Harry R. Price, P.E., F. SAME, Principal Engineer, NTH Consultants, hprice@nthconsultants.com, (313) 237-3935