U.S.
Department of the Interior
Bureau of Reclamation
PCCP: Condition Assessment, Repair, and Replacement
Strategies
Prestressed concrete cylinder pipe (PCCP) condition assessment and emergency response
plan development
Research Bulletin Problem
Science and Technology Program
Prestressed concrete cylinder pipe (PCCP) is used by Reclamation and other agencies for water conveyance, primarily as
S&T Project 7108 siphons on non-redundant transmission systems. Reclamation specified PCCP from approximately 1960 to 1990. Beginning
Prestressed concrete cylinder pipe (PCCP) is in 1984 and continuing through 2016, Reclamation has seen instances of both catastrophic failure and extreme deterioration
used by Reclamation and other agencies for of PCCP installations. Investigations have revealed problems with the PCCP including split, corroded, and broken wires
water conveyance, primarily as siphons on and damaged mortar coating. The primary failure seen in PCCP is compromised mortar coating and subsequent severe
non-redundant transmission systems. The corrosion of the prestressing wire. Unlike many other pipe types, failure of PCCP is typically by sudden rupture of the pipe
goal of this study was to survey the state wall. For this reason, it is important to have well-developed and actionable condition assessment and emergency response
of the art in PCCP condition assessment, plans for PCCP assets, and to know the risk of failure for each installation.
repair and service extension methods, and
replacement strategies to provide operators
with successful strategies for maintaining their Solution
PCCP assets.
The goal of this study was to survey the state of the art in PCCP condition assessment, repair and service extension
methods, and replacement strategies to provide operators with successful strategies for maintaining their PCCP assets.
Mission Issue
The study found techniques broken down into method overview, logistics of implementation, and order-of-magnitude
Improving the condition assessment, repair,
cost projections. This project also compiled Reclamation’s inventory of PCCP into a web-based geospatial database. The
and replacement plans for PCCP will allow
Reclamation to more efficiently manage its condition assessment is the first line of defense towards preventing a catastrophic failure of PCCP. Depending on site-
PCCP assets. specific needs and restrictions, some inspection techniques may be better suited than others. Even with a thorough condition
assessment plan, necessary repairs to sections of PCCP are inevitable. This report outlines commonly used techniques to
extend the service life of distressed PCCP including. Finally, when pipeline segments have deteriorated beyond repair,
Principal Investigator pipeline replacement projects must be considered. Proactive planning for replacement allows work to be budgeted and
Jessica Torrey scheduled and is much preferred to costly emergency replacements. This report outlines replacement methods.
Materials Engineer
Engineering & Laboratory Services Division
Technical Services Center
jtorrey@usbr.gov
Research Office Contact
Erin Foraker
Renewable Energy and Infrastructure
Research Coordinator
Research and Development Office
eforaker@usbr.gov
Tendon wrapping operations at Centennial Wash Siphon.
“The report is well done and will be very
informative to our Operating Entities on
Application and Results
Transferred Works and for our Reclamation
O&M Crews and Engineering support staff Condition assessment is the first line of defense towards preventing a catastrophic failure of PCCP. Combining inspection
on Reserved Works.” results with structural and analysis, a performance curve can be produced showing the number of wire breaks versus
operating pressure and the conditions that will produce cracking, yield, etc. After a baseline condition assessment has been
Geoff Keller established, further inspections can be performed on a scheduled basis as needed, for example every five to ten years. As
General Engineer the number of observed defects or detected wire breaks in a given section increases, the frequency of inspections can be
Bureau of Reclamation increased; or alternately, monitoring technology, such as acoustic fiber optic monitoring can be used.
Collaborators Condition assessment results are only useful to PCCP asset managers when followed up with either a plan for subsequent
Chris Duke inspections, or an actionable maintenance and repair plan. Proactively planning for necessary inspections, maintenance, and
Kylie Pelzer
repairs, both from a budgetary perspective and from scheduling perspective, can avoid the consequences demonstrated in
Water Conveyance
Bureau of Reclamation the case histories presented.
Ken Sayer
Civil Structures Future Plans
Bureau of Reclamation
Reclamation has several ongoing efforts in the field of PCCP management. The Policy Office- Asset Management Division
Patrick Wright
has a program to maintain the PCCP inventory and web-based viewer that was begun as part of this research project. It will
Adam Ricks
Geographic Applications & Analysis also fund, on a priority basis, baseline electromagnetic inspections for many Reclamation-owned PCCP and continue to
Organization feed that data, as well as risk assessments for each pipeline, into the GIS database.
Bureau of Reclamation
The Science & Technology Program has a three-year project to install an aboveground section of PCCP on the Denver
Nick Casamatta Federal Center as an educational demonstration and inspection method truthing specimen. The pipe should arrive in
Asset Management Division Denver in first quarter of FY 2020.
Bureau of Reclamation
More Information
https://www.usbr.gov/research/projects/detail.cfm?id=7108
Pre-impregnated CFRP sheets applied to interior walls of PCCP.
