Applications
What we do
Openaka provides comprehensive condition assessment information and management services for owners and operators of concrete pressure pipes, precast concrete products, concrete constructions and other concrete materials.
The firm focuses on four key areas:
- Internal Inspection
- Forensic investigations
- Design and oversight of pipe repair
- Structural analysis
Internal Inspection
Openaka has developed and uses a number of techniques for internal inspection of PCCP lines. These techniques have been used to identify and repair or replace over 150 pipes that were in a state of incipient failure.When assessing a PCCP main, an operator should determine whether or not it can be removed from service. If so, in most cases the first step of an assessment program should be to perform an internal inspection of the pipeline utilizing two inspection techniques:
- Visual and Sounding Inspection
- Electromagnetic Inspection
These two assessment techniques address each other’s limitations and enable the best possible baseline assessment to be ascertained.
In a Visual and Sounding Inspection trained personnel traverse a PCCP main in order to identify signs of distress. The inspectors visually examine the interior wall of the pipeline and sound the pipe’s surface with a hammer or rod. Certain types of cracks and “hollow sounding” areas are indicative of a loss of prestressing in a pipe section. In addition, faulty joints or other potential problems are documented.
Electromagnetic Inspections involve non-destructively testing the condition of the prestressing wire to identify electromagnetic anomalies consistent with wire break damage. By analyzing the electromagnetic anomalies, wire break damage can be identified and the number and location of wire breaks can be estimated. Pure Technologies’ P-Wave® electromagnetic inspection technology is used by Openaka personnel for this purpose.
Forensic Investigations
Forensic Investigations of PCCP may be needed after a pipeline failure, as part of a forensic evaluation, or to confirm the results of non-destructive testing. Openaka has performed numerous forensic evaluations of PCCP. These inspections have focused on the following aspects:
- Mortar coating sampling
- Wire sampling
- Ground water sampling
- Soil sampling
- Wire pitch determination
- Pipe dissection
- Resistivity testing
Openaka has investigated hundreds of PCCP failures. When performing such investigations the ultimate goal is to ensure another failure does not occur shortly after returning the pipe to service. Openaka has a standard protocol of inspection procedures to minimize the risk that the pipe will fail.
Design and oversight of pipe repair
One of Openaka’s specialisms is the provision of repair and strengthening designs for large diameter PCCP mains. Repairing large diameter PCCP is challenging and requires specific knowledge of how the pipes behave under construction loadings, especially when multiple repairs are performed in emergency situations.Openaka also consults on pipeline rehabilitation: from the preparation of drawings and creation of design specifications to overseeing and direct involvement in rehabilitation procedures.
Openaka is experienced in all available types of repair, including prestressed wire replacement, steel liner insertion, joint ring repair, tendon repair alternatives, carbon fiber repair, pipe encasement and individual pipe replacement.
Structural analysis
Openaka provides asset managers with expert analysis of the level of risk to the integrity of pipelines arising from broken wires within the structure of sections of PCCP.Our analysis determines how many wire breaks generate an unacceptable level of risk for a pipeline. One or two wire breaks may be acceptable. Hundreds of wire breaks is typically unacceptable. However, for most inspection projects, there are sections of pipe that fall between these levels of deterioration. Making proper engineering decisions on these pipe sections requires structural modeling to determine the level of risk.
The risk depends on many variables: wire break damage estimates, pipe design, depth of cover, operating pressure and surge pressures. Openaka’s structural modeling takes these variables into consideration to provide realistic answers on how to manage a pipeline.
The modeling efforts can range from more simplified techniques like the standard AWWA C301 pipe analysis to rigorous three dimensional finite element modeling. Openaka will use a model that is appropriate for a given pipeline working from the more simplified techniques to the more complex models, as warranted.